ICU 74.2: i18n/unicode/udat.h File Reference

ICU 74.2 74.2

Namespaces | Macros | Typedefs | Enumerations | Functions
udat.h File Reference

C API: DateFormat. More...

`#include "unicode/utypes.h"`
`#include "unicode/ucal.h"`
`#include "unicode/unum.h"`
`#include "unicode/udisplaycontext.h"`
`#include "unicode/ufieldpositer.h"`
`#include "unicode/localpointer.h"`

Go to the source code of this file.

## Namespaces
namespace | icu
| File coll.h.

## Macros
#define | UDAT_YEAR "y"
| Constant for date skeleton with year.
#define | UDAT_QUARTER "QQQQ"
| Constant for date skeleton with quarter.
#define | UDAT_ABBR_QUARTER "QQQ"
| Constant for date skeleton with abbreviated quarter.
#define | UDAT_YEAR_QUARTER "yQQQQ"
| Constant for date skeleton with year and quarter.
#define | UDAT_YEAR_ABBR_QUARTER "yQQQ"
| Constant for date skeleton with year and abbreviated quarter.
#define | UDAT_MONTH "MMMM"
| Constant for date skeleton with month.
#define | UDAT_ABBR_MONTH "MMM"
| Constant for date skeleton with abbreviated month.
#define | UDAT_NUM_MONTH "M"
| Constant for date skeleton with numeric month.
#define | UDAT_YEAR_MONTH "yMMMM"
| Constant for date skeleton with year and month.
#define | UDAT_YEAR_ABBR_MONTH "yMMM"
| Constant for date skeleton with year and abbreviated month.
#define | UDAT_YEAR_NUM_MONTH "yM"
| Constant for date skeleton with year and numeric month.
#define | UDAT_DAY "d"
| Constant for date skeleton with day.
#define | UDAT_YEAR_MONTH_DAY "yMMMMd"
| Constant for date skeleton with year, month, and day.
#define | UDAT_YEAR_ABBR_MONTH_DAY "yMMMd"
| Constant for date skeleton with year, abbreviated month, and day.
#define | UDAT_YEAR_NUM_MONTH_DAY "yMd"
| Constant for date skeleton with year, numeric month, and day.
#define | UDAT_WEEKDAY "EEEE"
| Constant for date skeleton with weekday.
#define | UDAT_ABBR_WEEKDAY "E"
| Constant for date skeleton with abbreviated weekday.
#define | UDAT_YEAR_MONTH_WEEKDAY_DAY "yMMMMEEEEd"
| Constant for date skeleton with year, month, weekday, and day.
#define | UDAT_YEAR_ABBR_MONTH_WEEKDAY_DAY "yMMMEd"
| Constant for date skeleton with year, abbreviated month, weekday, and day.
#define | UDAT_YEAR_NUM_MONTH_WEEKDAY_DAY "yMEd"
| Constant for date skeleton with year, numeric month, weekday, and day.
#define | UDAT_MONTH_DAY "MMMMd"
| Constant for date skeleton with long month and day.
#define | UDAT_ABBR_MONTH_DAY "MMMd"
| Constant for date skeleton with abbreviated month and day.
#define | UDAT_NUM_MONTH_DAY "Md"
| Constant for date skeleton with numeric month and day.
#define | UDAT_MONTH_WEEKDAY_DAY "MMMMEEEEd"
| Constant for date skeleton with month, weekday, and day.
#define | UDAT_ABBR_MONTH_WEEKDAY_DAY "MMMEd"
| Constant for date skeleton with abbreviated month, weekday, and day.
#define | UDAT_NUM_MONTH_WEEKDAY_DAY "MEd"
| Constant for date skeleton with numeric month, weekday, and day.
#define | UDAT_HOUR "j"
| Constant for date skeleton with hour, with the locale's preferred hour format (12 or 24).
#define | UDAT_HOUR24 "H"
| Constant for date skeleton with hour in 24-hour presentation.
#define | UDAT_MINUTE "m"
| Constant for date skeleton with minute.
#define | UDAT_HOUR_MINUTE "jm"
| Constant for date skeleton with hour and minute, with the locale's preferred hour format (12 or 24).
#define | UDAT_HOUR24_MINUTE "Hm"
| Constant for date skeleton with hour and minute in 24-hour presentation.
#define | UDAT_SECOND "s"
| Constant for date skeleton with second.
#define | UDAT_HOUR_MINUTE_SECOND "jms"
| Constant for date skeleton with hour, minute, and second, with the locale's preferred hour format (12 or 24).
#define | UDAT_HOUR24_MINUTE_SECOND "Hms"
| Constant for date skeleton with hour, minute, and second in 24-hour presentation.
#define | UDAT_MINUTE_SECOND "ms"
| Constant for date skeleton with minute and second.
#define | UDAT_LOCATION_TZ "VVVV"
| Constant for generic location format, such as Los Angeles Time; used in combinations date + time + zone, or time + zone.
#define | UDAT_GENERIC_TZ "vvvv"
| Constant for generic non-location format, such as Pacific Time; used in combinations date + time + zone, or time + zone.
#define | UDAT_ABBR_GENERIC_TZ "v"
| Constant for generic non-location format, abbreviated if possible, such as PT; used in combinations date + time + zone, or time + zone.
#define | UDAT_SPECIFIC_TZ "zzzz"
| Constant for specific non-location format, such as Pacific Daylight Time; used in combinations date + time + zone, or time + zone.
#define | UDAT_ABBR_SPECIFIC_TZ "z"
| Constant for specific non-location format, abbreviated if possible, such as PDT; used in combinations date + time + zone, or time + zone.
#define | UDAT_ABBR_UTC_TZ "ZZZZ"
| Constant for localized GMT/UTC format, such as GMT+8:00 or HPG-8:00; used in combinations date + time + zone, or time + zone.
#define | UDAT_STANDALONE_MONTH "LLLL"
| Constant for date skeleton with standalone month.
#define | UDAT_ABBR_STANDALONE_MONTH "LLL"
| Constant for date skeleton with standalone abbreviated month.
#define | UDAT_HOUR_MINUTE_GENERIC_TZ "jmv"
| Constant for date skeleton with hour, minute, and generic timezone.
#define | UDAT_HOUR_MINUTE_TZ "jmz"
| Constant for date skeleton with hour, minute, and timezone.
#define | UDAT_HOUR_GENERIC_TZ "jv"
| Constant for date skeleton with hour and generic timezone.
#define | UDAT_HOUR_TZ "jz"
| Constant for date skeleton with hour and timezone.
#define | JP_ERA_2019_ROOT "Reiwa"
| Constant for Unicode string name of new (in 2019) Japanese calendar era, root/English abbreviated version (ASCII-range characters).
#define | JP_ERA_2019_JA "\\u4EE4\\u548C"
| Constant for Unicode string name of new (in 2019) Japanese calendar era, Japanese abbreviated version (Han, or fullwidth Latin for testing).
#define | JP_ERA_2019_NARROW "R"
| Constant for Unicode string name of new (in 2019) Japanese calendar era, root and Japanese narrow version (ASCII-range characters).
#define | UDAT_HAS_PATTERN_CHAR_FOR_TIME_SEPARATOR 0
| Is a pattern character defined for UDAT_TIME_SEPARATOR_FIELD? In ICU 55 it was COLON, but that was withdrawn in ICU 56.

## Typedefs
typedef void * | UDateFormat
| A date formatter.
typedef enum UDateFormatStyle | UDateFormatStyle
| The possible date/time format styles.
typedef enum UDateFormatField | UDateFormatField
| FieldPosition and UFieldPosition selectors for format fields defined by DateFormat and UDateFormat.
typedef enum UDateFormatBooleanAttribute | UDateFormatBooleanAttribute
| DateFormat boolean attributes.
typedef enum UDateFormatHourCycle | UDateFormatHourCycle
| Hour Cycle.
typedef enum UDateFormatSymbolType | UDateFormatSymbolType
| The possible types of date format symbols.
typedef struct UDateFormatSymbols | UDateFormatSymbols
| Date format symbols.
typedef UDateFormat *(* | UDateFormatOpener) (UDateFormatStyle timeStyle, UDateFormatStyle dateStyle, const char *locale, const UChar *tzID, int32_t tzIDLength, const UChar *pattern, int32_t patternLength, UErrorCode *status)

## Enumerations
enum | UDateFormatStyle { UDAT_FULL , UDAT_LONG , UDAT_MEDIUM , UDAT_SHORT , UDAT_DEFAULT = UDAT_MEDIUM , UDAT_RELATIVE = (1 << 7) , UDAT_FULL_RELATIVE = UDAT_FULL | UDAT_RELATIVE , UDAT_LONG_RELATIVE = UDAT_LONG | UDAT_RELATIVE , UDAT_MEDIUM_RELATIVE = UDAT_MEDIUM | UDAT_RELATIVE , UDAT_SHORT_RELATIVE = UDAT_SHORT | UDAT_RELATIVE , UDAT_NONE = -1 , UDAT_PATTERN = -2 , UDAT_IGNORE = UDAT_PATTERN }
| The possible date/time format styles. More...
enum | UDateFormatField { UDAT_ERA_FIELD = 0 , UDAT_YEAR_FIELD = 1 , UDAT_MONTH_FIELD = 2 , UDAT_DATE_FIELD = 3 , UDAT_HOUR_OF_DAY1_FIELD = 4 , UDAT_HOUR_OF_DAY0_FIELD = 5 , UDAT_MINUTE_FIELD = 6 , UDAT_SECOND_FIELD = 7 , UDAT_FRACTIONAL_SECOND_FIELD = 8 , UDAT_DAY_OF_WEEK_FIELD = 9 , UDAT_DAY_OF_YEAR_FIELD = 10 , UDAT_DAY_OF_WEEK_IN_MONTH_FIELD = 11 , UDAT_WEEK_OF_YEAR_FIELD = 12 , UDAT_WEEK_OF_MONTH_FIELD = 13 , UDAT_AM_PM_FIELD = 14 , UDAT_HOUR1_FIELD = 15 , UDAT_HOUR0_FIELD = 16 , UDAT_TIMEZONE_FIELD = 17 , UDAT_YEAR_WOY_FIELD = 18 , UDAT_DOW_LOCAL_FIELD = 19 , UDAT_EXTENDED_YEAR_FIELD = 20 , UDAT_JULIAN_DAY_FIELD = 21 , UDAT_MILLISECONDS_IN_DAY_FIELD = 22 , UDAT_TIMEZONE_RFC_FIELD = 23 , UDAT_TIMEZONE_GENERIC_FIELD = 24 , UDAT_STANDALONE_DAY_FIELD = 25 , UDAT_STANDALONE_MONTH_FIELD = 26 , UDAT_QUARTER_FIELD = 27 , UDAT_STANDALONE_QUARTER_FIELD = 28 , UDAT_TIMEZONE_SPECIAL_FIELD = 29 , UDAT_YEAR_NAME_FIELD = 30 , UDAT_TIMEZONE_LOCALIZED_GMT_OFFSET_FIELD = 31 , UDAT_TIMEZONE_ISO_FIELD = 32 , UDAT_TIMEZONE_ISO_LOCAL_FIELD = 33 , UDAT_RELATED_YEAR_FIELD = 34 , UDAT_AM_PM_MIDNIGHT_NOON_FIELD = 35 , UDAT_FLEXIBLE_DAY_PERIOD_FIELD = 36 , UDAT_TIME_SEPARATOR_FIELD = 37 , UDAT_FIELD_COUNT = 38 }
| FieldPosition and UFieldPosition selectors for format fields defined by DateFormat and UDateFormat. More...
enum | UDateFormatBooleanAttribute { UDAT_PARSE_ALLOW_WHITESPACE = 0 , UDAT_PARSE_ALLOW_NUMERIC = 1 , UDAT_PARSE_PARTIAL_LITERAL_MATCH = 2 , UDAT_PARSE_MULTIPLE_PATTERNS_FOR_MATCH = 3 , UDAT_BOOLEAN_ATTRIBUTE_COUNT = 4 }
| DateFormat boolean attributes. More...
enum | UDateFormatHourCycle { UDAT_HOUR_CYCLE_11 , UDAT_HOUR_CYCLE_12 , UDAT_HOUR_CYCLE_23 , UDAT_HOUR_CYCLE_24 }
| Hour Cycle. More...
enum | UDateFormatSymbolType { UDAT_ERAS , UDAT_MONTHS , UDAT_SHORT_MONTHS , UDAT_WEEKDAYS , UDAT_SHORT_WEEKDAYS , UDAT_AM_PMS , UDAT_LOCALIZED_CHARS , UDAT_ERA_NAMES , UDAT_NARROW_MONTHS , UDAT_NARROW_WEEKDAYS , UDAT_STANDALONE_MONTHS , UDAT_STANDALONE_SHORT_MONTHS , UDAT_STANDALONE_NARROW_MONTHS , UDAT_STANDALONE_WEEKDAYS , UDAT_STANDALONE_SHORT_WEEKDAYS , UDAT_STANDALONE_NARROW_WEEKDAYS , UDAT_QUARTERS , UDAT_SHORT_QUARTERS , UDAT_STANDALONE_QUARTERS , UDAT_STANDALONE_SHORT_QUARTERS , UDAT_SHORTER_WEEKDAYS , UDAT_STANDALONE_SHORTER_WEEKDAYS , UDAT_CYCLIC_YEARS_WIDE , UDAT_CYCLIC_YEARS_ABBREVIATED , UDAT_CYCLIC_YEARS_NARROW , UDAT_ZODIAC_NAMES_WIDE , UDAT_ZODIAC_NAMES_ABBREVIATED , UDAT_ZODIAC_NAMES_NARROW , UDAT_NARROW_QUARTERS , UDAT_STANDALONE_NARROW_QUARTERS }
| The possible types of date format symbols. More...

## Functions
U_CAPI UCalendarDateFields | udat_toCalendarDateField (UDateFormatField field)
| Maps from a UDateFormatField to the corresponding UCalendarDateFields.
U_CAPI UDateFormat * | udat_open (UDateFormatStyle timeStyle, UDateFormatStyle dateStyle, const char *locale, const UChar *tzID, int32_t tzIDLength, const UChar *pattern, int32_t patternLength, UErrorCode *status)
| Open a new UDateFormat for formatting and parsing dates and times.
U_CAPI void | udat_close (UDateFormat *format)
| Close a UDateFormat.
U_CAPI UBool | udat_getBooleanAttribute (const UDateFormat *fmt, UDateFormatBooleanAttribute attr, UErrorCode *status)
| Get a boolean attribute associated with a UDateFormat.
U_CAPI void | udat_setBooleanAttribute (UDateFormat *fmt, UDateFormatBooleanAttribute attr, UBool newValue, UErrorCode *status)
| Set a boolean attribute associated with a UDateFormat.
U_CAPI UDateFormat * | udat_clone (const UDateFormat *fmt, UErrorCode *status)
| Open a copy of a UDateFormat.
U_CAPI int32_t | udat_format (const UDateFormat *format, UDate dateToFormat, UChar *result, int32_t resultLength, UFieldPosition *position, UErrorCode *status)
| Format a date using a UDateFormat.
U_CAPI int32_t | udat_formatCalendar (const UDateFormat *format, UCalendar *calendar, UChar *result, int32_t capacity, UFieldPosition *position, UErrorCode *status)
| Format a date using an UDateFormat.
U_CAPI int32_t | udat_formatForFields (const UDateFormat *format, UDate dateToFormat, UChar *result, int32_t resultLength, UFieldPositionIterator *fpositer, UErrorCode *status)
| Format a date using a UDateFormat.
U_CAPI int32_t | udat_formatCalendarForFields (const UDateFormat *format, UCalendar *calendar, UChar *result, int32_t capacity, UFieldPositionIterator *fpositer, UErrorCode *status)
| Format a date using a UDateFormat.
U_CAPI UDate | udat_parse (const UDateFormat *format, const UChar *text, int32_t textLength, int32_t *parsePos, UErrorCode *status)
| Parse a string into an date/time using a UDateFormat.
U_CAPI void | udat_parseCalendar (const UDateFormat *format, UCalendar *calendar, const UChar *text, int32_t textLength, int32_t *parsePos, UErrorCode *status)
| Parse a string into an date/time using a UDateFormat.
U_CAPI UBool | udat_isLenient (const UDateFormat *fmt)
| Determine if an UDateFormat will perform lenient parsing.
U_CAPI void | udat_setLenient (UDateFormat *fmt, UBool isLenient)
| Specify whether an UDateFormat will perform lenient parsing.
U_CAPI const UCalendar * | udat_getCalendar (const UDateFormat *fmt)
| Get the UCalendar associated with an UDateFormat.
U_CAPI void | udat_setCalendar (UDateFormat *fmt, const UCalendar *calendarToSet)
| Set the UCalendar associated with an UDateFormat.
U_CAPI const UNumberFormat * | udat_getNumberFormat (const UDateFormat *fmt)
| Get the UNumberFormat associated with an UDateFormat.
U_CAPI const UNumberFormat * | udat_getNumberFormatForField (const UDateFormat *fmt, UChar field)
| Get the UNumberFormat for specific field associated with an UDateFormat.
U_CAPI void | udat_adoptNumberFormatForFields (UDateFormat *fmt, const UChar *fields, UNumberFormat *numberFormatToSet, UErrorCode *status)
| Set the UNumberFormat for specific field associated with an UDateFormat.
U_CAPI void | udat_setNumberFormat (UDateFormat *fmt, const UNumberFormat *numberFormatToSet)
| Set the UNumberFormat associated with an UDateFormat.
U_CAPI void | udat_adoptNumberFormat (UDateFormat *fmt, UNumberFormat *numberFormatToAdopt)
| Adopt the UNumberFormat associated with an UDateFormat.
U_CAPI const char * | udat_getAvailable (int32_t localeIndex)
| Get a locale for which date/time formatting patterns are available.
U_CAPI int32_t | udat_countAvailable (void)
| Determine how many locales have date/time formatting patterns available.
U_CAPI UDate | udat_get2DigitYearStart (const UDateFormat *fmt, UErrorCode *status)
| Get the year relative to which all 2-digit years are interpreted.
U_CAPI void | udat_set2DigitYearStart (UDateFormat *fmt, UDate d, UErrorCode *status)
| Set the year relative to which all 2-digit years will be interpreted.
U_CAPI int32_t | udat_toPattern (const UDateFormat *fmt, UBool localized, UChar *result, int32_t resultLength, UErrorCode *status)
| Extract the pattern from a UDateFormat.
U_CAPI void | udat_applyPattern (UDateFormat *format, UBool localized, const UChar *pattern, int32_t patternLength)
| Set the pattern used by an UDateFormat.
U_CAPI int32_t | udat_getSymbols (const UDateFormat *fmt, UDateFormatSymbolType type, int32_t symbolIndex, UChar *result, int32_t resultLength, UErrorCode *status)
| Get the symbols associated with an UDateFormat.
U_CAPI int32_t | udat_countSymbols (const UDateFormat *fmt, UDateFormatSymbolType type)
| Count the number of particular symbols for an UDateFormat.
U_CAPI void | udat_setSymbols (UDateFormat *format, UDateFormatSymbolType type, int32_t symbolIndex, UChar *value, int32_t valueLength, UErrorCode *status)
| Set the symbols associated with an UDateFormat.
U_CAPI const char * | udat_getLocaleByType (const UDateFormat *fmt, ULocDataLocaleType type, UErrorCode *status)
| Get the locale for this date format object.
U_CAPI void | udat_setContext (UDateFormat *fmt, UDisplayContext value, UErrorCode *status)
| Set a particular UDisplayContext value in the formatter, such as UDISPCTX_CAPITALIZATION_FOR_STANDALONE.
U_CAPI UDisplayContext | udat_getContext (const UDateFormat *fmt, UDisplayContextType type, UErrorCode *status)
| Get the formatter's UDisplayContext value for the specified UDisplayContextType, such as UDISPCTX_TYPE_CAPITALIZATION.
U_CAPI int32_t | udat_toPatternRelativeDate (const UDateFormat *fmt, UChar *result, int32_t resultLength, UErrorCode *status)
| Extract the date pattern from a UDateFormat set for relative date formatting.
U_CAPI int32_t | udat_toPatternRelativeTime (const UDateFormat *fmt, UChar *result, int32_t resultLength, UErrorCode *status)
| Extract the time pattern from a UDateFormat set for relative date formatting.
U_CAPI void | udat_applyPatternRelative (UDateFormat *format, const UChar *datePattern, int32_t datePatternLength, const UChar *timePattern, int32_t timePatternLength, UErrorCode *status)
| Set the date & time patterns used by a UDateFormat set for relative date formatting.
U_CAPI void | udat_registerOpener (UDateFormatOpener opener, UErrorCode *status)
| Register a provider factory.
U_CAPI UDateFormatOpener | udat_unregisterOpener (UDateFormatOpener opener, UErrorCode *status)
| Un-Register a provider factory.

## Detailed Description

C API: DateFormat.

## Date Format C API

Date Format C API consists of functions that convert dates and times from their internal representations to textual form and back again in a language-independent manner. Converting from the internal representation (milliseconds since midnight, January 1, 1970) to text is known as "formatting," and converting from text to millis is known as "parsing." We currently define only one concrete structure UDateFormat, which can handle pretty much all normal date formatting and parsing actions.

Date Format helps you to format and parse dates for any locale. Your code can be completely independent of the locale conventions for months, days of the week, or even the calendar format: lunar vs. solar.

To format a date for the current Locale with default time and date style, use one of the static factory methods:

    UErrorCode status = U_ZERO_ERROR;
    UChar *myString;
    int32_t myStrlen = 0;
    UDateFormat* dfmt = udat_open(UDAT_DEFAULT, UDAT_DEFAULT, NULL, NULL, -1, NULL, -1, &status);
    myStrlen = udat_format(dfmt, myDate, NULL, myStrlen, NULL, &status);
    if (status==U_BUFFER_OVERFLOW_ERROR){
        status=U_ZERO_ERROR;
        myString=(UChar*)malloc(sizeof(UChar) * (myStrlen+1) );
        udat_format(dfmt, myDate, myString, myStrlen+1, NULL, &status);
    }
    UDateFormatvoid * UDateFormatA date formatter.Definition udat.h:157
    udat_openU_CAPI UDateFormat * udat_open(UDateFormatStyle timeStyle, UDateFormatStyle dateStyle, const char *locale, const UChar *tzID, int32_t tzIDLength, const UChar *pattern, int32_t patternLength, UErrorCode *status)Open a new UDateFormat for formatting and parsing dates and times.
    udat_formatU_CAPI int32_t udat_format(const UDateFormat *format, UDate dateToFormat, UChar *result, int32_t resultLength, UFieldPosition *position, UErrorCode *status)Format a date using a UDateFormat.
    UDAT_DEFAULT@ UDAT_DEFAULTDefault style.Definition udat.h:172
    UCharchar16_t UCharThe base type for UTF-16 code units and pointers.Definition umachine.h:386
    NULL#define NULLDefine NULL if necessary, to nullptr for C++ and to ((void *)0) for C.Definition utypes.h:188
    UErrorCodeUErrorCodeStandard ICU4C error code type, a substitute for exceptions.Definition utypes.h:415
    U_BUFFER_OVERFLOW_ERROR@ U_BUFFER_OVERFLOW_ERRORA result would not fit in the supplied buffer.Definition utypes.h:465
    U_ZERO_ERROR@ U_ZERO_ERRORNo error, no warning.Definition utypes.h:449

If you are formatting multiple numbers, it is more efficient to get the format and use it multiple times so that the system doesn't have to fetch the information about the local language and country conventions multiple times.

    UErrorCode status = U_ZERO_ERROR;
    int32_t i, myStrlen = 0;
    UChar* myString;
    char buffer[1024];
    UDate myDateArr[] = { 0.0, 100000000.0, 2000000000.0 }; // test values
    UDateFormat* df = udat_open(UDAT_DEFAULT, UDAT_DEFAULT, NULL, NULL, -1, NULL, 0, &status);
    for (i = 0; i < 3; i++) {
        myStrlen = udat_format(df, myDateArr[i], NULL, myStrlen, NULL, &status);
        if(status == U_BUFFER_OVERFLOW_ERROR){
            status = U_ZERO_ERROR;
            myString = (UChar*)malloc(sizeof(UChar) * (myStrlen+1) );
            udat_format(df, myDateArr[i], myString, myStrlen+1, NULL, &status);
            printf("%s\n", u_austrcpy(buffer, myString) );
            free(myString);
        }
    }
    u_austrcpyU_CAPI char * u_austrcpy(char *dst, const UChar *src)Copy ustring to a byte string encoded in the default codepage.
    UDatedouble UDateDate and Time data type.Definition utypes.h:203

To get specific fields of a date, you can use UFieldPosition to get specific fields.

    UErrorCode status = U_ZERO_ERROR;
    UFieldPosition pos;
    UChar *myString;
    int32_t myStrlen = 0;
    char buffer[1024];

    pos.field = 1;  // Same as the DateFormat::EField enum
    UDateFormat* dfmt = udat_open(UDAT_DEFAULT, UDAT_DEFAULT, NULL, -1, NULL, 0, &status);
    myStrlen = udat_format(dfmt, myDate, NULL, myStrlen, &pos, &status);
    if (status==U_BUFFER_OVERFLOW_ERROR){
        status=U_ZERO_ERROR;
        myString=(UChar*)malloc(sizeof(UChar) * (myStrlen+1) );
        udat_format(dfmt, myDate, myString, myStrlen+1, &pos, &status);
    }
    printf("date format: %s\n", u_austrcpy(buffer, myString));
    buffer[pos.endIndex] = 0;   // NULL terminate the string.
    printf("UFieldPosition position equals %s\n", &buffer[pos.beginIndex]);
    UFieldPositionA struct representing a range of text containing a specific field.Definition umisc.h:34
    UFieldPosition::fieldint32_t fieldThe field.Definition umisc.h:39
    UFieldPosition::beginIndexint32_t beginIndexThe start of the text range containing field.Definition umisc.h:44
    UFieldPosition::endIndexint32_t endIndexThe limit of the text range containing field.Definition umisc.h:49

To format a date for a different Locale, specify it in the call to udat_open()

    UDateFormat* df = udat_open(UDAT_SHORT, UDAT_SHORT, "fr_FR", NULL, -1, NULL, 0, &status);
    UDAT_SHORT@ UDAT_SHORTShort style.Definition udat.h:170

You can use a DateFormat API udat_parse() to parse.

    UErrorCode status = U_ZERO_ERROR;
    int32_t parsepos=0;
    UDate myDate = udat_parse(df, myString, u_strlen(myString), &parsepos, &status);
    u_strlenU_CAPI int32_t u_strlen(const UChar *s)
    udat_parseU_CAPI UDate udat_parse(const UDateFormat *format, const UChar *text, int32_t textLength, int32_t *parsePos, UErrorCode *status)Parse a string into an date/time using a UDateFormat.

You can pass in different options for the arguments for date and time style to control the length of the result; from SHORT to MEDIUM to LONG to FULL. The exact result depends on the locale, but generally: see UDateFormatStyle for more details

- UDAT_SHORT is completely numeric, such as 12/13/52 or 3:30pm
- UDAT_MEDIUM is longer, such as Jan 12, 1952
- UDAT_LONG is longer, such as January 12, 1952 or 3:30:32pm
- UDAT_FULL is pretty completely specified, such as Tuesday, April 12, 1952 AD or 3:30:42pm PST.

You can also set the time zone on the format if you wish.

You can also use forms of the parse and format methods with Parse Position and UFieldPosition to allow you to

- Progressively parse through pieces of a string.
- Align any particular field, or find out where it is for selection on the screen.

Date and Time Patterns:

Date and time formats are specified by date and time pattern strings. Within date and time pattern strings, all unquoted ASCII letters [A-Za-z] are reserved as pattern letters representing calendar fields. `UDateFormat` supports the date and time formatting algorithm and pattern letters defined by UTS#35 Unicode Locale Data Markup Language (LDML) and further documented for ICU in the ICU User Guide.

Definition in file udat.h.

## Macro Definition Documentation

## ◆ JP_ERA_2019_JA

#define JP_ERA_2019_JA "\\u4EE4\\u548C"

Constant for Unicode string name of new (in 2019) Japanese calendar era, Japanese abbreviated version (Han, or fullwidth Latin for testing).

Internal:
  Do not use. This API is for internal use only.

Definition at line 501 of file udat.h.

## ◆ JP_ERA_2019_NARROW

#define JP_ERA_2019_NARROW "R"

Constant for Unicode string name of new (in 2019) Japanese calendar era, root and Japanese narrow version (ASCII-range characters).

Internal:
  Do not use. This API is for internal use only.

Definition at line 507 of file udat.h.

## ◆ JP_ERA_2019_ROOT

#define JP_ERA_2019_ROOT "Reiwa"

Constant for Unicode string name of new (in 2019) Japanese calendar era, root/English abbreviated version (ASCII-range characters).

Internal:
  Do not use. This API is for internal use only.

Definition at line 495 of file udat.h.

## ◆ UDAT_ABBR_GENERIC_TZ

#define UDAT_ABBR_GENERIC_TZ "v"

Constant for generic non-location format, abbreviated if possible, such as PT; used in combinations date + time + zone, or time + zone.

See also
  LDML Date Format Patterns
  LDML Time Zone Fallback

Stable:
  ICU 51

Definition at line 427 of file udat.h.

## ◆ UDAT_ABBR_MONTH

#define UDAT_ABBR_MONTH "MMM"

Constant for date skeleton with abbreviated month.

Stable:
  ICU 4.0

Definition at line 238 of file udat.h.

## ◆ UDAT_ABBR_MONTH_DAY

#define UDAT_ABBR_MONTH_DAY "MMMd"

Constant for date skeleton with abbreviated month and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 321 of file udat.h.

## ◆ UDAT_ABBR_MONTH_WEEKDAY_DAY

#define UDAT_ABBR_MONTH_WEEKDAY_DAY "MMMEd"

Constant for date skeleton with abbreviated month, weekday, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 339 of file udat.h.

## ◆ UDAT_ABBR_QUARTER

#define UDAT_ABBR_QUARTER "QQQ"

Constant for date skeleton with abbreviated quarter.

Stable:
  ICU 51

Definition at line 218 of file udat.h.

## ◆ UDAT_ABBR_SPECIFIC_TZ

#define UDAT_ABBR_SPECIFIC_TZ "z"

Constant for specific non-location format, abbreviated if possible, such as PDT; used in combinations date + time + zone, or time + zone.

See also
  LDML Date Format Patterns
  LDML Time Zone Fallback

Stable:
  ICU 51

Definition at line 443 of file udat.h.

## ◆ UDAT_ABBR_STANDALONE_MONTH

#define UDAT_ABBR_STANDALONE_MONTH "LLL"

Constant for date skeleton with standalone abbreviated month.

Deprecated:
  ICU 50 Use UDAT_ABBR_MONTH instead.

Definition at line 465 of file udat.h.

## ◆ UDAT_ABBR_UTC_TZ

#define UDAT_ABBR_UTC_TZ "ZZZZ"

Constant for localized GMT/UTC format, such as GMT+8:00 or HPG-8:00; used in combinations date + time + zone, or time + zone.

See also
  LDML Date Format Patterns
  LDML Time Zone Fallback

Stable:
  ICU 51

Definition at line 451 of file udat.h.

## ◆ UDAT_ABBR_WEEKDAY

#define UDAT_ABBR_WEEKDAY "E"

Constant for date skeleton with abbreviated weekday.

Stable:
  ICU 51

Definition at line 291 of file udat.h.

## ◆ UDAT_DAY

#define UDAT_DAY "d"

Constant for date skeleton with day.

Stable:
  ICU 4.0

Definition at line 263 of file udat.h.

## ◆ UDAT_GENERIC_TZ

#define UDAT_GENERIC_TZ "vvvv"

Constant for generic non-location format, such as Pacific Time; used in combinations date + time + zone, or time + zone.

See also
  LDML Date Format Patterns
  LDML Time Zone Fallback

Stable:
  ICU 51

Definition at line 419 of file udat.h.

## ◆ UDAT_HAS_PATTERN_CHAR_FOR_TIME_SEPARATOR

#define UDAT_HAS_PATTERN_CHAR_FOR_TIME_SEPARATOR 0

Is a pattern character defined for UDAT_TIME_SEPARATOR_FIELD? In ICU 55 it was COLON, but that was withdrawn in ICU 56.

Internal:
  Do not use. This API is for internal use only. ICU 56

Definition at line 833 of file udat.h.

## ◆ UDAT_HOUR

#define UDAT_HOUR "j"

Constant for date skeleton with hour, with the locale's preferred hour format (12 or 24).

Stable:
  ICU 4.0

Definition at line 353 of file udat.h.

## ◆ UDAT_HOUR24

#define UDAT_HOUR24 "H"

Constant for date skeleton with hour in 24-hour presentation.

Stable:
  ICU 51

Definition at line 358 of file udat.h.

## ◆ UDAT_HOUR24_MINUTE

#define UDAT_HOUR24_MINUTE "Hm"

Constant for date skeleton with hour and minute in 24-hour presentation.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 375 of file udat.h.

## ◆ UDAT_HOUR24_MINUTE_SECOND

#define UDAT_HOUR24_MINUTE_SECOND "Hms"

Constant for date skeleton with hour, minute, and second in 24-hour presentation.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 394 of file udat.h.

## ◆ UDAT_HOUR_GENERIC_TZ

#define UDAT_HOUR_GENERIC_TZ "jv"

Constant for date skeleton with hour and generic timezone.

Deprecated:
  ICU 50 Use instead UDAT_HOUR UDAT_ABBR_GENERIC_TZ or some other timezone presentation.

Definition at line 481 of file udat.h.

## ◆ UDAT_HOUR_MINUTE

#define UDAT_HOUR_MINUTE "jm"

Constant for date skeleton with hour and minute, with the locale's preferred hour format (12 or 24).

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 369 of file udat.h.

## ◆ UDAT_HOUR_MINUTE_GENERIC_TZ

#define UDAT_HOUR_MINUTE_GENERIC_TZ "jmv"

Constant for date skeleton with hour, minute, and generic timezone.

Deprecated:
  ICU 50 Use instead UDAT_HOUR_MINUTE UDAT_ABBR_GENERIC_TZ or some other timezone presentation.

Definition at line 471 of file udat.h.

## ◆ UDAT_HOUR_MINUTE_SECOND

#define UDAT_HOUR_MINUTE_SECOND "jms"

Constant for date skeleton with hour, minute, and second, with the locale's preferred hour format (12 or 24).

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 387 of file udat.h.

## ◆ UDAT_HOUR_MINUTE_TZ

#define UDAT_HOUR_MINUTE_TZ "jmz"

Constant for date skeleton with hour, minute, and timezone.

Deprecated:
  ICU 50 Use instead UDAT_HOUR_MINUTE UDAT_ABBR_SPECIFIC_TZ or some other timezone presentation.

Definition at line 476 of file udat.h.

## ◆ UDAT_HOUR_TZ

#define UDAT_HOUR_TZ "jz"

Constant for date skeleton with hour and timezone.

Deprecated:
  ICU 50 Use instead UDAT_HOUR UDAT_ABBR_SPECIFIC_TZ or some other timezone presentation.

Definition at line 486 of file udat.h.

## ◆ UDAT_LOCATION_TZ

#define UDAT_LOCATION_TZ "VVVV"

Constant for generic location format, such as Los Angeles Time; used in combinations date + time + zone, or time + zone.

See also
  LDML Date Format Patterns
  LDML Time Zone Fallback

Stable:
  ICU 51

Definition at line 411 of file udat.h.

## ◆ UDAT_MINUTE

#define UDAT_MINUTE "m"

Constant for date skeleton with minute.

Stable:
  ICU 51

Definition at line 363 of file udat.h.

## ◆ UDAT_MINUTE_SECOND

#define UDAT_MINUTE_SECOND "ms"

Constant for date skeleton with minute and second.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 400 of file udat.h.

## ◆ UDAT_MONTH

#define UDAT_MONTH "MMMM"

Constant for date skeleton with month.

Stable:
  ICU 4.0

Definition at line 233 of file udat.h.

## ◆ UDAT_MONTH_DAY

#define UDAT_MONTH_DAY "MMMMd"

Constant for date skeleton with long month and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 315 of file udat.h.

## ◆ UDAT_MONTH_WEEKDAY_DAY

#define UDAT_MONTH_WEEKDAY_DAY "MMMMEEEEd"

Constant for date skeleton with month, weekday, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 333 of file udat.h.

## ◆ UDAT_NUM_MONTH

#define UDAT_NUM_MONTH "M"

Constant for date skeleton with numeric month.

Stable:
  ICU 4.0

Definition at line 243 of file udat.h.

## ◆ UDAT_NUM_MONTH_DAY

#define UDAT_NUM_MONTH_DAY "Md"

Constant for date skeleton with numeric month and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 327 of file udat.h.

## ◆ UDAT_NUM_MONTH_WEEKDAY_DAY

#define UDAT_NUM_MONTH_WEEKDAY_DAY "MEd"

Constant for date skeleton with numeric month, weekday, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 345 of file udat.h.

## ◆ UDAT_QUARTER

#define UDAT_QUARTER "QQQQ"

Constant for date skeleton with quarter.

Stable:
  ICU 51

Definition at line 213 of file udat.h.

## ◆ UDAT_SECOND

#define UDAT_SECOND "s"

Constant for date skeleton with second.

Stable:
  ICU 51

Definition at line 380 of file udat.h.

## ◆ UDAT_SPECIFIC_TZ

#define UDAT_SPECIFIC_TZ "zzzz"

Constant for specific non-location format, such as Pacific Daylight Time; used in combinations date + time + zone, or time + zone.

See also
  LDML Date Format Patterns
  LDML Time Zone Fallback

Stable:
  ICU 51

Definition at line 435 of file udat.h.

## ◆ UDAT_STANDALONE_MONTH

#define UDAT_STANDALONE_MONTH "LLLL"

Constant for date skeleton with standalone month.

Deprecated:
  ICU 50 Use UDAT_MONTH instead.

Definition at line 460 of file udat.h.

## ◆ UDAT_WEEKDAY

#define UDAT_WEEKDAY "EEEE"

Constant for date skeleton with weekday.

Stable:
  ICU 51

Definition at line 286 of file udat.h.

## ◆ UDAT_YEAR

#define UDAT_YEAR "y"

Constant for date skeleton with year.

Stable:
  ICU 4.0

Definition at line 208 of file udat.h.

## ◆ UDAT_YEAR_ABBR_MONTH

#define UDAT_YEAR_ABBR_MONTH "yMMM"

Constant for date skeleton with year and abbreviated month.

Stable:
  ICU 4.0

Definition at line 253 of file udat.h.

## ◆ UDAT_YEAR_ABBR_MONTH_DAY

#define UDAT_YEAR_ABBR_MONTH_DAY "yMMMd"

Constant for date skeleton with year, abbreviated month, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 275 of file udat.h.

## ◆ UDAT_YEAR_ABBR_MONTH_WEEKDAY_DAY

#define UDAT_YEAR_ABBR_MONTH_WEEKDAY_DAY "yMMMEd"

Constant for date skeleton with year, abbreviated month, weekday, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 303 of file udat.h.

## ◆ UDAT_YEAR_ABBR_QUARTER

#define UDAT_YEAR_ABBR_QUARTER "yQQQ"

Constant for date skeleton with year and abbreviated quarter.

Stable:
  ICU 4.0

Definition at line 228 of file udat.h.

## ◆ UDAT_YEAR_MONTH

#define UDAT_YEAR_MONTH "yMMMM"

Constant for date skeleton with year and month.

Stable:
  ICU 4.0

Definition at line 248 of file udat.h.

## ◆ UDAT_YEAR_MONTH_DAY

#define UDAT_YEAR_MONTH_DAY "yMMMMd"

Constant for date skeleton with year, month, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 269 of file udat.h.

## ◆ UDAT_YEAR_MONTH_WEEKDAY_DAY

#define UDAT_YEAR_MONTH_WEEKDAY_DAY "yMMMMEEEEd"

Constant for date skeleton with year, month, weekday, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 297 of file udat.h.

## ◆ UDAT_YEAR_NUM_MONTH

#define UDAT_YEAR_NUM_MONTH "yM"

Constant for date skeleton with year and numeric month.

Stable:
  ICU 4.0

Definition at line 258 of file udat.h.

## ◆ UDAT_YEAR_NUM_MONTH_DAY

#define UDAT_YEAR_NUM_MONTH_DAY "yMd"

Constant for date skeleton with year, numeric month, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 281 of file udat.h.

## ◆ UDAT_YEAR_NUM_MONTH_WEEKDAY_DAY

#define UDAT_YEAR_NUM_MONTH_WEEKDAY_DAY "yMEd"

Constant for date skeleton with year, numeric month, weekday, and day.

Used in combinations date + time, date + time + zone, or time + zone.

Stable:
  ICU 4.0

Definition at line 309 of file udat.h.

## ◆ UDAT_YEAR_QUARTER

#define UDAT_YEAR_QUARTER "yQQQQ"

Constant for date skeleton with year and quarter.

Stable:
  ICU 4.0

Definition at line 223 of file udat.h.

## Typedef Documentation

## ◆ UDateFormat

typedef void* UDateFormat

A date formatter.

For usage in C programs.

Stable:
  ICU 2.6

Definition at line 157 of file udat.h.

## ◆ UDateFormatBooleanAttribute

typedef enum UDateFormatBooleanAttribute UDateFormatBooleanAttribute

DateFormat boolean attributes.

Stable:
  ICU 53

## ◆ UDateFormatField

typedef enum UDateFormatField UDateFormatField

FieldPosition and UFieldPosition selectors for format fields defined by DateFormat and UDateFormat.

Stable:
  ICU 3.0

## ◆ UDateFormatHourCycle

typedef enum UDateFormatHourCycle UDateFormatHourCycle

Hour Cycle.

Stable:
  ICU 67

## ◆ UDateFormatOpener

typedef UDateFormat *(* UDateFormatOpener) (UDateFormatStyle timeStyle, UDateFormatStyle dateStyle, const char *locale, const UChar *tzID, int32_t tzIDLength, const UChar *pattern, int32_t patternLength, UErrorCode *status)

Internal:
  Do not use. This API is for internal use only.

See also
  udat_open

Definition at line 1714 of file udat.h.

## ◆ UDateFormatStyle

typedef enum UDateFormatStyle UDateFormatStyle

The possible date/time format styles.

Stable:
  ICU 2.6

## ◆ UDateFormatSymbols

typedef struct UDateFormatSymbols UDateFormatSymbols

Date format symbols.

For usage in C programs.

Stable:
  ICU 2.6

Definition at line 1553 of file udat.h.

## ◆ UDateFormatSymbolType

typedef enum UDateFormatSymbolType UDateFormatSymbolType

The possible types of date format symbols.

Stable:
  ICU 2.6

## Enumeration Type Documentation

## ◆ UDateFormatBooleanAttribute

enum UDateFormatBooleanAttribute

DateFormat boolean attributes.

Stable:
  ICU 53

Enumerator
UDAT_PARSE_ALLOW_WHITESPACE | indicates whether whitespace is allowed. Includes trailing dot tolerance. Stable: ICU 53
UDAT_PARSE_ALLOW_NUMERIC | indicates tolerance of numeric data when String data may be assumed. eg: UDAT_YEAR_NAME_FIELD, UDAT_STANDALONE_MONTH_FIELD, UDAT_DAY_OF_WEEK_FIELD Stable: ICU 53
UDAT_PARSE_PARTIAL_LITERAL_MATCH | indicates tolerance of a partial literal match e.g. accepting "--mon-02-march-2011" for a pattern of "'--: 'EEE-WW-MMMM-yyyy" Stable: ICU 56
UDAT_PARSE_MULTIPLE_PATTERNS_FOR_MATCH | indicates tolerance of pattern mismatch between input data and specified format pattern. e.g. accepting "September" for a month pattern of MMM ("Sep") Stable: ICU 56
UDAT_BOOLEAN_ATTRIBUTE_COUNT | One more than the highest normal UDateFormatBooleanAttribute value. Deprecated: ICU 58 The numeric value may change over time, see ICU ticket #12420.

Definition at line 917 of file udat.h.

## ◆ UDateFormatField

enum UDateFormatField

FieldPosition and UFieldPosition selectors for format fields defined by DateFormat and UDateFormat.

Stable:
  ICU 3.0

Enumerator
UDAT_ERA_FIELD | FieldPosition and UFieldPosition selector for 'G' field alignment, corresponding to the UCAL_ERA field. Stable: ICU 3.0
UDAT_YEAR_FIELD | FieldPosition and UFieldPosition selector for 'y' field alignment, corresponding to the UCAL_YEAR field. Stable: ICU 3.0
UDAT_MONTH_FIELD | FieldPosition and UFieldPosition selector for 'M' field alignment, corresponding to the UCAL_MONTH field. Stable: ICU 3.0
UDAT_DATE_FIELD | FieldPosition and UFieldPosition selector for 'd' field alignment, corresponding to the UCAL_DATE field. Stable: ICU 3.0
UDAT_HOUR_OF_DAY1_FIELD | FieldPosition and UFieldPosition selector for 'k' field alignment, corresponding to the UCAL_HOUR_OF_DAY field. UDAT_HOUR_OF_DAY1_FIELD is used for the one-based 24-hour clock. For example, 23:59 + 01:00 results in 24:59. Stable: ICU 3.0
UDAT_HOUR_OF_DAY0_FIELD | FieldPosition and UFieldPosition selector for 'H' field alignment, corresponding to the UCAL_HOUR_OF_DAY field. UDAT_HOUR_OF_DAY0_FIELD is used for the zero-based 24-hour clock. For example, 23:59 + 01:00 results in 00:59. Stable: ICU 3.0
UDAT_MINUTE_FIELD | FieldPosition and UFieldPosition selector for 'm' field alignment, corresponding to the UCAL_MINUTE field. Stable: ICU 3.0
UDAT_SECOND_FIELD | FieldPosition and UFieldPosition selector for 's' field alignment, corresponding to the UCAL_SECOND field. Stable: ICU 3.0
UDAT_FRACTIONAL_SECOND_FIELD | FieldPosition and UFieldPosition selector for 'S' field alignment, corresponding to the UCAL_MILLISECOND field. Note: Time formats that use 'S' can display a maximum of three significant digits for fractional seconds, corresponding to millisecond resolution and a fractional seconds sub-pattern of SSS. If the sub-pattern is S or SS, the fractional seconds value will be truncated (not rounded) to the number of display places specified. If the fractional seconds sub-pattern is longer than SSS, the additional display places will be filled with zeros. Stable: ICU 3.0
UDAT_DAY_OF_WEEK_FIELD | FieldPosition and UFieldPosition selector for 'E' field alignment, corresponding to the UCAL_DAY_OF_WEEK field. Stable: ICU 3.0
UDAT_DAY_OF_YEAR_FIELD | FieldPosition and UFieldPosition selector for 'D' field alignment, corresponding to the UCAL_DAY_OF_YEAR field. Stable: ICU 3.0
UDAT_DAY_OF_WEEK_IN_MONTH_FIELD | FieldPosition and UFieldPosition selector for 'F' field alignment, corresponding to the UCAL_DAY_OF_WEEK_IN_MONTH field. Stable: ICU 3.0
UDAT_WEEK_OF_YEAR_FIELD | FieldPosition and UFieldPosition selector for 'w' field alignment, corresponding to the UCAL_WEEK_OF_YEAR field. Stable: ICU 3.0
UDAT_WEEK_OF_MONTH_FIELD | FieldPosition and UFieldPosition selector for 'W' field alignment, corresponding to the UCAL_WEEK_OF_MONTH field. Stable: ICU 3.0
UDAT_AM_PM_FIELD | FieldPosition and UFieldPosition selector for 'a' field alignment, corresponding to the UCAL_AM_PM field. Stable: ICU 3.0
UDAT_HOUR1_FIELD | FieldPosition and UFieldPosition selector for 'h' field alignment, corresponding to the UCAL_HOUR field. UDAT_HOUR1_FIELD is used for the one-based 12-hour clock. For example, 11:30 PM + 1 hour results in 12:30 AM. Stable: ICU 3.0
UDAT_HOUR0_FIELD | FieldPosition and UFieldPosition selector for 'K' field alignment, corresponding to the UCAL_HOUR field. UDAT_HOUR0_FIELD is used for the zero-based 12-hour clock. For example, 11:30 PM + 1 hour results in 00:30 AM. Stable: ICU 3.0
UDAT_TIMEZONE_FIELD | FieldPosition and UFieldPosition selector for 'z' field alignment, corresponding to the UCAL_ZONE_OFFSET and UCAL_DST_OFFSET fields. Stable: ICU 3.0
UDAT_YEAR_WOY_FIELD | FieldPosition and UFieldPosition selector for 'Y' field alignment, corresponding to the UCAL_YEAR_WOY field. Stable: ICU 3.0
UDAT_DOW_LOCAL_FIELD | FieldPosition and UFieldPosition selector for 'e' field alignment, corresponding to the UCAL_DOW_LOCAL field. Stable: ICU 3.0
UDAT_EXTENDED_YEAR_FIELD | FieldPosition and UFieldPosition selector for 'u' field alignment, corresponding to the UCAL_EXTENDED_YEAR field. Stable: ICU 3.0
UDAT_JULIAN_DAY_FIELD | FieldPosition and UFieldPosition selector for 'g' field alignment, corresponding to the UCAL_JULIAN_DAY field. Stable: ICU 3.0
UDAT_MILLISECONDS_IN_DAY_FIELD | FieldPosition and UFieldPosition selector for 'A' field alignment, corresponding to the UCAL_MILLISECONDS_IN_DAY field. Stable: ICU 3.0
UDAT_TIMEZONE_RFC_FIELD | FieldPosition and UFieldPosition selector for 'Z' field alignment, corresponding to the UCAL_ZONE_OFFSET and UCAL_DST_OFFSET fields. Stable: ICU 3.0
UDAT_TIMEZONE_GENERIC_FIELD | FieldPosition and UFieldPosition selector for 'v' field alignment, corresponding to the UCAL_ZONE_OFFSET field. Stable: ICU 3.4
UDAT_STANDALONE_DAY_FIELD | FieldPosition selector for 'c' field alignment, corresponding to the `UCAL_DOW_LOCAL` field. This displays the stand alone day name, if available. Stable: ICU 3.4
UDAT_STANDALONE_MONTH_FIELD | FieldPosition selector for 'L' field alignment, corresponding to the `UCAL_MONTH` field. This displays the stand alone month name, if available. Stable: ICU 3.4
UDAT_QUARTER_FIELD | FieldPosition selector for "Q" field alignment, corresponding to quarters. This is implemented using the `UCAL_MONTH` field. This displays the quarter. Stable: ICU 3.6
UDAT_STANDALONE_QUARTER_FIELD | FieldPosition selector for the "q" field alignment, corresponding to stand-alone quarters. This is implemented using the `UCAL_MONTH` field. This displays the stand-alone quarter. Stable: ICU 3.6
UDAT_TIMEZONE_SPECIAL_FIELD | FieldPosition and UFieldPosition selector for 'V' field alignment, corresponding to the UCAL_ZONE_OFFSET field. Stable: ICU 3.8
UDAT_YEAR_NAME_FIELD | FieldPosition selector for "U" field alignment, corresponding to cyclic year names. This is implemented using the `UCAL_YEAR` field. This displays the cyclic year name, if available. Stable: ICU 49
UDAT_TIMEZONE_LOCALIZED_GMT_OFFSET_FIELD | FieldPosition selector for 'O' field alignment, corresponding to the UCAL_ZONE_OFFSET and UCAL_DST_OFFSETfields. This displays the localized GMT format. Stable: ICU 51
UDAT_TIMEZONE_ISO_FIELD | FieldPosition selector for 'X' field alignment, corresponding to the UCAL_ZONE_OFFSET and UCAL_DST_OFFSETfields. This displays the ISO 8601 local time offset format or UTC indicator ("Z"). Stable: ICU 51
UDAT_TIMEZONE_ISO_LOCAL_FIELD | FieldPosition selector for 'x' field alignment, corresponding to the UCAL_ZONE_OFFSET and UCAL_DST_OFFSET fields. This displays the ISO 8601 local time offset format. Stable: ICU 51
UDAT_RELATED_YEAR_FIELD | FieldPosition and UFieldPosition selector for 'r' field alignment, no directly corresponding UCAL_ field. Internal: Do not use. This API is for internal use only. ICU 53
UDAT_AM_PM_MIDNIGHT_NOON_FIELD | FieldPosition selector for 'b' field alignment. Displays midnight and noon for 12am and 12pm, respectively, if available; otherwise fall back to AM / PM. Stable: ICU 57
UDAT_TIME_SEPARATOR_FIELD | FieldPosition and UFieldPosition selector for time separator, no corresponding UCAL_ field. No pattern character is currently defined for this. Internal: Do not use. This API is for internal use only.
UDAT_FIELD_COUNT | Number of FieldPosition and UFieldPosition selectors for DateFormat and UDateFormat. Valid selectors range from 0 to UDAT_FIELD_COUNT-1. Deprecated: ICU 58 The numeric value may change over time, see ICU ticket #12420.

Definition at line 515 of file udat.h.

## ◆ UDateFormatHourCycle

enum UDateFormatHourCycle

Hour Cycle.

Stable:
  ICU 67

Enumerator
UDAT_HOUR_CYCLE_11 | Hour in am/pm (0~11) Stable: ICU 67
UDAT_HOUR_CYCLE_12 | Hour in am/pm (1~12) Stable: ICU 67
UDAT_HOUR_CYCLE_23 | Hour in day (0~23) Stable: ICU 67
UDAT_HOUR_CYCLE_24 | Hour in day (1~24) Stable: ICU 67

Definition at line 983 of file udat.h.

## ◆ UDateFormatStyle

enum UDateFormatStyle

The possible date/time format styles.

Stable:
  ICU 2.6

Enumerator
UDAT_FULL | Full style.
UDAT_LONG | Long style.
UDAT_MEDIUM | Medium style.
UDAT_SHORT | Short style.
UDAT_DEFAULT | Default style.
UDAT_RELATIVE | Bitfield for relative date.
UDAT_NONE | No style.
UDAT_PATTERN | Use the pattern given in the parameter to udat_open. See also udat_open Stable: ICU 50
UDAT_IGNORE | Internal: Do not use. This API is for internal use only. alias to UDAT_PATTERN

Definition at line 162 of file udat.h.

## ◆ UDateFormatSymbolType

enum UDateFormatSymbolType

The possible types of date format symbols.

Stable:
  ICU 2.6

Enumerator
UDAT_ERAS | The era names, for example AD.
UDAT_MONTHS | The month names, for example February.
UDAT_SHORT_MONTHS | The short month names, for example Feb.
UDAT_WEEKDAYS | The CLDR-style format "wide" weekday names, for example Monday.
UDAT_SHORT_WEEKDAYS | The CLDR-style format "abbreviated" (not "short") weekday names, for example "Mon." For the CLDR-style format "short" weekday names, use UDAT_SHORTER_WEEKDAYS.
UDAT_AM_PMS | The AM/PM names, for example AM.
UDAT_LOCALIZED_CHARS | The localized characters.
UDAT_ERA_NAMES | The long era names, for example Anno Domini.
UDAT_NARROW_MONTHS | The narrow month names, for example F.
UDAT_NARROW_WEEKDAYS | The CLDR-style format "narrow" weekday names, for example "M".
UDAT_STANDALONE_MONTHS | Standalone context versions of months.
UDAT_STANDALONE_WEEKDAYS | The CLDR-style stand-alone "wide" weekday names.
UDAT_STANDALONE_SHORT_WEEKDAYS | The CLDR-style stand-alone "abbreviated" (not "short") weekday names. For the CLDR-style stand-alone "short" weekday names, use UDAT_STANDALONE_SHORTER_WEEKDAYS.
UDAT_STANDALONE_NARROW_WEEKDAYS | The CLDR-style stand-alone "narrow" weekday names.
UDAT_QUARTERS | The quarters, for example 1st Quarter.
UDAT_SHORT_QUARTERS | The short quarter names, for example Q1.
UDAT_STANDALONE_QUARTERS | Standalone context versions of quarters.
UDAT_SHORTER_WEEKDAYS | The CLDR-style short weekday names, e.g. "Su", Mo", etc. These are named "SHORTER" to contrast with the constants using SHORT above, which actually get the CLDR-style abbreviated versions of the corresponding names. Stable: ICU 51
UDAT_STANDALONE_SHORTER_WEEKDAYS | Standalone version of UDAT_SHORTER_WEEKDAYS. Stable: ICU 51
UDAT_CYCLIC_YEARS_WIDE | Cyclic year names (only supported for some calendars, and only for FORMAT usage; udat_setSymbols not supported for UDAT_CYCLIC_YEARS_WIDE) Stable: ICU 54
UDAT_CYCLIC_YEARS_ABBREVIATED | Cyclic year names (only supported for some calendars, and only for FORMAT usage) Stable: ICU 54
UDAT_CYCLIC_YEARS_NARROW | Cyclic year names (only supported for some calendars, and only for FORMAT usage; udat_setSymbols not supported for UDAT_CYCLIC_YEARS_NARROW) Stable: ICU 54
UDAT_ZODIAC_NAMES_WIDE | Calendar zodiac names (only supported for some calendars, and only for FORMAT usage; udat_setSymbols not supported for UDAT_ZODIAC_NAMES_WIDE) Stable: ICU 54
UDAT_ZODIAC_NAMES_ABBREVIATED | Calendar zodiac names (only supported for some calendars, and only for FORMAT usage) Stable: ICU 54
UDAT_ZODIAC_NAMES_NARROW | Calendar zodiac names (only supported for some calendars, and only for FORMAT usage; udat_setSymbols not supported for UDAT_ZODIAC_NAMES_NARROW) Stable: ICU 54
UDAT_NARROW_QUARTERS | The narrow quarter names, for example 1. Stable: ICU 70
UDAT_STANDALONE_NARROW_QUARTERS | The narrow standalone quarter names, for example 1. Stable: ICU 70

Definition at line 1443 of file udat.h.

## Function Documentation

## ◆ udat_adoptNumberFormat()

U_CAPI void udat_adoptNumberFormat | ( | UDateFormat * | fmt,
|  | UNumberFormat * | numberFormatToAdopt
| ) |  |

Adopt the UNumberFormat associated with an UDateFormat.

A UDateFormat uses a UNumberFormat to format numbers within a date, for example the day number.

Parameters

  fmt | The formatter to set.
  numberFormatToAdopt | A pointer to the UNumberFormat to be used by fmt to format numbers.

See also
  udat_getNumberFormat

Stable:
  ICU 54

## ◆ udat_adoptNumberFormatForFields()

U_CAPI void udat_adoptNumberFormatForFields | ( | UDateFormat * | fmt,
|  | const UChar * | fields,
|  | UNumberFormat * | numberFormatToSet,
|  | UErrorCode * | status
| ) |  |

Set the UNumberFormat for specific field associated with an UDateFormat.

It can be a single field like: "y"(year) or "M"(month) It can be several field combined together: "yM"(year and month) Note: 1 symbol field is enough for multiple symbol field (so "y" will override "yy", "yyy") If the field is not numeric, then override has no effect (like "MMM" will use abbreviation, not numerical field)

Parameters

  fields | the fields to set
  fmt | The formatter to set.
  numberFormatToSet | A pointer to the UNumberFormat to be used by fmt to format numbers.
  status | error code passed around (memory allocation or invalid fields)

See also
  udat_getNumberFormatForField

Stable:
  ICU 54

## ◆ udat_applyPattern()

U_CAPI void udat_applyPattern | ( | UDateFormat * | format,
|  | UBool | localized,
|  | const UChar * | pattern,
|  | int32_t | patternLength
| ) |  |

Set the pattern used by an UDateFormat.

The pattern should follow the pattern syntax rules.

Parameters

  format | The formatter to set.
  localized | true if the pattern is localized, false otherwise.
  pattern | The new pattern
  patternLength | The length of pattern, or -1 if null-terminated.

See also
  udat_toPattern

Stable:
  ICU 2.0

## ◆ udat_applyPatternRelative()

U_CAPI void udat_applyPatternRelative | ( | UDateFormat * | format,
|  | const UChar * | datePattern,
|  | int32_t | datePatternLength,
|  | const UChar * | timePattern,
|  | int32_t | timePatternLength,
|  | UErrorCode * | status
| ) |  |

Set the date & time patterns used by a UDateFormat set for relative date formatting.

The patterns should follow the pattern syntax rules.

Parameters

  format | The formatter to set.
  datePattern | The new date pattern
  datePatternLength | The length of datePattern, or -1 if null-terminated.
  timePattern | The new time pattern
  timePatternLength | The length of timePattern, or -1 if null-terminated.
  status | A pointer to a UErrorCode to receive any errors

See also
  udat_toPatternRelativeDate, udat_toPatternRelativeTime

Internal:
  Do not use. This API is for internal use only. ICU 4.2 technology preview

## ◆ udat_clone()

U_CAPI UDateFormat * udat_clone | ( | const UDateFormat * | fmt,
|  | UErrorCode * | status
| ) |  |

Open a copy of a UDateFormat.

This function performs a deep copy.

Parameters

  fmt | The format to copy
  status | A pointer to an UErrorCode to receive any errors.

Returns
  A pointer to a UDateFormat identical to fmt.

Stable:
  ICU 2.0

## ◆ udat_close()

U_CAPI void udat_close | ( | UDateFormat * | format | ) |

Close a UDateFormat.

Once closed, a UDateFormat may no longer be used.

Parameters

  format | The formatter to close.

Stable:
  ICU 2.0

## ◆ udat_countAvailable()

U_CAPI int32_t udat_countAvailable | ( | void |  | ) |

Determine how many locales have date/time formatting patterns available.

This function is most useful as determining the loop ending condition for calls to `udat_getAvailable`.

Returns
  The number of locales for which date/time formatting patterns are available.

See also
  udat_getAvailable

Stable:
  ICU 2.0

## ◆ udat_countSymbols()

U_CAPI int32_t udat_countSymbols | ( | const UDateFormat * | fmt,
|  | UDateFormatSymbolType | type
| ) |  |

Count the number of particular symbols for an UDateFormat.

This function is most useful as for determining the loop termination condition for calls to `udat_getSymbols`.

Parameters

  fmt | The formatter to query.
  type | The type of symbols to count. One of UDAT_ERAS, UDAT_MONTHS, UDAT_SHORT_MONTHS, UDAT_WEEKDAYS, UDAT_SHORT_WEEKDAYS, UDAT_AM_PMS, or UDAT_LOCALIZED_CHARS

Returns
  The number of symbols of type type.

See also
  udat_getSymbols
  udat_setSymbols

Stable:
  ICU 2.0

## ◆ udat_format()

U_CAPI int32_t udat_format | ( | const UDateFormat * | format,
|  | UDate | dateToFormat,
|  | UChar * | result,
|  | int32_t | resultLength,
|  | UFieldPosition * | position,
|  | UErrorCode * | status
| ) |  |

Format a date using a UDateFormat.

The date will be formatted using the conventions specified in `udat_open`

Parameters

  format | The formatter to use
  dateToFormat | The date to format
  result | A pointer to a buffer to receive the formatted number.
  resultLength | The maximum size of result.
  position | A pointer to a UFieldPosition. On input, position->field is read. On output, position->beginIndex and position->endIndex indicate the beginning and ending indices of field number position->field, if such a field exists. This parameter may be NULL, in which case no field position data is returned.
  status | A pointer to an UErrorCode to receive any errors

Returns
  The total buffer size needed; if greater than resultLength, the output was truncated.

See also
  udat_parse
  UFieldPosition

Stable:
  ICU 2.0

## ◆ udat_formatCalendar()

U_CAPI int32_t udat_formatCalendar | ( | const UDateFormat * | format,
|  | UCalendar * | calendar,
|  | UChar * | result,
|  | int32_t | capacity,
|  | UFieldPosition * | position,
|  | UErrorCode * | status
| ) |  |

Format a date using an UDateFormat.

The date will be formatted using the conventions specified in `udat_open`

Parameters

  format | The formatter to use
  calendar | The calendar to format. The calendar instance might be mutated if fields are not yet fully calculated, though the function won't change the logical date and time held by the instance.
  result | A pointer to a buffer to receive the formatted number.
  capacity | The maximum size of result.
  position | A pointer to a UFieldPosition. On input, position->field is read. On output, position->beginIndex and position->endIndex indicate the beginning and ending indices of field number position->field, if such a field exists. This parameter may be NULL, in which case no field position data is returned.
  status | A pointer to an UErrorCode to receive any errors

Returns
  The total buffer size needed; if greater than resultLength, the output was truncated.

See also
  udat_format
  udat_parseCalendar
  UFieldPosition

Stable:
  ICU 55

## ◆ udat_formatCalendarForFields()

U_CAPI int32_t udat_formatCalendarForFields | ( | const UDateFormat * | format,
|  | UCalendar * | calendar,
|  | UChar * | result,
|  | int32_t | capacity,
|  | UFieldPositionIterator * | fpositer,
|  | UErrorCode * | status
| ) |  |

Format a date using a UDateFormat.

The date will be formatted using the conventions specified in `udat_open`

Parameters

  format | The formatter to use
  calendar | The calendar to format. The calendar instance might be mutated if fields are not yet fully calculated, though the function won't change the logical date and time held by the instance.
  result | A pointer to a buffer to receive the formatted number.
  capacity | The maximum size of result.
  fpositer | A pointer to a UFieldPositionIterator created by `ufieldpositer_open` (may be NULL if field position information is not needed). Any iteration information already present in the UFieldPositionIterator will be deleted, and the iterator will be reset to apply to the fields in the formatted string created by this function call; the field values provided by `ufieldpositer_next` will be from the UDateFormatField enum.
  status | A pointer to a UErrorCode to receive any errors

Returns
  The total buffer size needed; if greater than resultLength, the output was truncated.

See also
  udat_format
  udat_parseCalendar
  UFieldPositionIterator

Stable:
  ICU 55

## ◆ udat_formatForFields()

U_CAPI int32_t udat_formatForFields | ( | const UDateFormat * | format,
|  | UDate | dateToFormat,
|  | UChar * | result,
|  | int32_t | resultLength,
|  | UFieldPositionIterator * | fpositer,
|  | UErrorCode * | status
| ) |  |

Format a date using a UDateFormat.

The date will be formatted using the conventions specified in `udat_open`

Parameters

  format | The formatter to use
  dateToFormat | The date to format
  result | A pointer to a buffer to receive the formatted number.
  resultLength | The maximum size of result.
  fpositer | A pointer to a UFieldPositionIterator created by `ufieldpositer_open` (may be NULL if field position information is not needed). Any iteration information already present in the UFieldPositionIterator will be deleted, and the iterator will be reset to apply to the fields in the formatted string created by this function call; the field values provided by `ufieldpositer_next` will be from the UDateFormatField enum.
  status | A pointer to a UErrorCode to receive any errors

Returns
  The total buffer size needed; if greater than resultLength, the output was truncated.

See also
  udat_parse
  UFieldPositionIterator

Stable:
  ICU 55

## ◆ udat_get2DigitYearStart()

U_CAPI UDate udat_get2DigitYearStart | ( | const UDateFormat * | fmt,
|  | UErrorCode * | status
| ) |  |

Get the year relative to which all 2-digit years are interpreted.

For example, if the 2-digit start year is 2100, the year 99 will be interpreted as 2199.

Parameters

  fmt | The formatter to query.
  status | A pointer to an UErrorCode to receive any errors

Returns
  The year relative to which all 2-digit years are interpreted.

See also
  udat_Set2DigitYearStart

Stable:
  ICU 2.0

## ◆ udat_getAvailable()

U_CAPI const char * udat_getAvailable | ( | int32_t | localeIndex | ) |

Get a locale for which date/time formatting patterns are available.

A UDateFormat in a locale returned by this function will perform the correct formatting and parsing for the locale.

Parameters

  localeIndex | The index of the desired locale.

Returns
  A locale for which date/time formatting patterns are available, or 0 if none.

See also
  udat_countAvailable

Stable:
  ICU 2.0

## ◆ udat_getBooleanAttribute()

U_CAPI UBool udat_getBooleanAttribute | ( | const UDateFormat * | fmt,
|  | UDateFormatBooleanAttribute | attr,
|  | UErrorCode * | status
| ) |  |

Get a boolean attribute associated with a UDateFormat.

An example would be a true value for a key of UDAT_PARSE_ALLOW_WHITESPACE indicating allowing whitespace leniency. If the formatter does not understand the attribute, -1 is returned.

Parameters

  fmt | The formatter to query.
  attr | The attribute to query; e.g. UDAT_PARSE_ALLOW_WHITESPACE.
  status | A pointer to an UErrorCode to receive any errors

Returns
  The value of attr.

Stable:
  ICU 53

## ◆ udat_getCalendar()

U_CAPI const UCalendar * udat_getCalendar | ( | const UDateFormat * | fmt | ) |

Get the UCalendar associated with an UDateFormat.

A UDateFormat uses a UCalendar to convert a raw value to, for example, the day of the week.

Parameters

  fmt | The formatter to query.

Returns
  A pointer to the UCalendar used by fmt.

See also
  udat_setCalendar

Stable:
  ICU 2.0

## ◆ udat_getContext()

U_CAPI UDisplayContext udat_getContext | ( | const UDateFormat * | fmt,
|  | UDisplayContextType | type,
|  | UErrorCode * | status
| ) |  |

Get the formatter's UDisplayContext value for the specified UDisplayContextType, such as UDISPCTX_TYPE_CAPITALIZATION.

Parameters

  fmt | The formatter to query.
  type | The UDisplayContextType whose value to return
  status | A pointer to an UErrorCode to receive any errors

Returns
  The UDisplayContextValue for the specified type.

Stable:
  ICU 53

## ◆ udat_getLocaleByType()

U_CAPI const char * udat_getLocaleByType | ( | const UDateFormat * | fmt,
|  | ULocDataLocaleType | type,
|  | UErrorCode * | status
| ) |  |

Get the locale for this date format object.

You can choose between valid and actual locale.

Parameters

  fmt | The formatter to get the locale from
  type | type of the locale we're looking for (valid or actual)
  status | error code for the operation

Returns
  the locale name

Stable:
  ICU 2.8

## ◆ udat_getNumberFormat()

U_CAPI const UNumberFormat * udat_getNumberFormat | ( | const UDateFormat * | fmt | ) |

Get the UNumberFormat associated with an UDateFormat.

A UDateFormat uses a UNumberFormat to format numbers within a date, for example the day number.

Parameters

  fmt | The formatter to query.

Returns
  A pointer to the UNumberFormat used by fmt to format numbers.

See also
  udat_setNumberFormat

Stable:
  ICU 2.0

## ◆ udat_getNumberFormatForField()

U_CAPI const UNumberFormat * udat_getNumberFormatForField | ( | const UDateFormat * | fmt,
|  | UChar | field
| ) |  |

Get the UNumberFormat for specific field associated with an UDateFormat.

For example: 'y' for year and 'M' for month

Parameters

  fmt | The formatter to query.
  field | the field to query

Returns
  A pointer to the UNumberFormat used by fmt to format field numbers.

See also
  udat_setNumberFormatForField

Stable:
  ICU 54

## ◆ udat_getSymbols()

U_CAPI int32_t udat_getSymbols | ( | const UDateFormat * | fmt,
|  | UDateFormatSymbolType | type,
|  | int32_t | symbolIndex,
|  | UChar * | result,
|  | int32_t | resultLength,
|  | UErrorCode * | status
| ) |  |

Get the symbols associated with an UDateFormat.

The symbols are what a UDateFormat uses to represent locale-specific data, for example month or day names.

Parameters

  fmt | The formatter to query.
  type | The type of symbols to get. One of UDAT_ERAS, UDAT_MONTHS, UDAT_SHORT_MONTHS, UDAT_WEEKDAYS, UDAT_SHORT_WEEKDAYS, UDAT_AM_PMS, or UDAT_LOCALIZED_CHARS
  symbolIndex | The desired symbol of type type.
  result | A pointer to a buffer to receive the pattern.
  resultLength | The maximum size of result.
  status | A pointer to an UErrorCode to receive any errors

Returns
  The total buffer size needed; if greater than resultLength, the output was truncated.

See also
  udat_countSymbols
  udat_setSymbols

Stable:
  ICU 2.0

## ◆ udat_isLenient()

U_CAPI UBool udat_isLenient | ( | const UDateFormat * | fmt | ) |

Determine if an UDateFormat will perform lenient parsing.

With lenient parsing, the parser may use heuristics to interpret inputs that do not precisely match the pattern. With strict parsing, inputs must match the pattern.

Parameters

  fmt | The formatter to query

Returns
  true if fmt is set to perform lenient parsing, false otherwise.

See also
  udat_setLenient

Stable:
  ICU 2.0

## ◆ udat_open()

U_CAPI UDateFormat * udat_open | ( | UDateFormatStyle | timeStyle,
|  | UDateFormatStyle | dateStyle,
|  | const char * | locale,
|  | const UChar * | tzID,
|  | int32_t | tzIDLength,
|  | const UChar * | pattern,
|  | int32_t | patternLength,
|  | UErrorCode * | status
| ) |  |

Open a new UDateFormat for formatting and parsing dates and times.

A UDateFormat may be used to format dates in calls to `udat_format`, and to parse dates in calls to `udat_parse`.

Parameters

  timeStyle | The style used to format times; one of UDAT_FULL, UDAT_LONG, UDAT_MEDIUM, UDAT_SHORT, UDAT_DEFAULT, or UDAT_NONE (relative time styles are not currently supported). When the pattern parameter is used, pass in UDAT_PATTERN for both timeStyle and dateStyle.
  dateStyle | The style used to format dates; one of UDAT_FULL, UDAT_LONG, UDAT_MEDIUM, UDAT_SHORT, UDAT_DEFAULT, UDAT_FULL_RELATIVE, UDAT_LONG_RELATIVE, UDAT_MEDIUM_RELATIVE, UDAT_SHORT_RELATIVE, or UDAT_NONE. When the pattern parameter is used, pass in UDAT_PATTERN for both timeStyle and dateStyle. As currently implemented, relative date formatting only affects a limited range of calendar days before or after the current date, based on the CLDR <field type="day">/<relative> data: For example, in English, "Yesterday", "Today", and "Tomorrow". Outside of this range, dates are formatted using the corresponding non-relative style.
  locale | The locale specifying the formatting conventions
  tzID | A timezone ID specifying the timezone to use. If 0, use the default timezone.
  tzIDLength | The length of tzID, or -1 if null-terminated.
  pattern | A pattern specifying the format to use.
  patternLength | The number of characters in the pattern, or -1 if null-terminated.
  status | A pointer to an UErrorCode to receive any errors

Returns
  A pointer to a UDateFormat to use for formatting dates and times, or 0 if an error occurred.

Stable:
  ICU 2.0

## ◆ udat_parse()

U_CAPI UDate udat_parse | ( | const UDateFormat * | format,
|  | const UChar * | text,
|  | int32_t | textLength,
|  | int32_t * | parsePos,
|  | UErrorCode * | status
| ) |  |

Parse a string into an date/time using a UDateFormat.

The date will be parsed using the conventions specified in `udat_open`.

Note that the normal date formats associated with some calendars - such as the Chinese lunar calendar - do not specify enough fields to enable dates to be parsed unambiguously. In the case of the Chinese lunar calendar, while the year within the current 60-year cycle is specified, the number of such cycles since the start date of the calendar (in the UCAL_ERA field of the UCalendar object) is not normally part of the format, and parsing may assume the wrong era. For cases such as this it is recommended that clients parse using udat_parseCalendar with the UCalendar passed in set to the current date, or to a date within the era/cycle that should be assumed if absent in the format.

Parameters

  format | The formatter to use.
  text | The text to parse.
  textLength | The length of text, or -1 if null-terminated.
  parsePos | If not 0, on input a pointer to an integer specifying the offset at which to begin parsing. If not 0, on output the offset at which parsing ended.
  status | A pointer to an UErrorCode to receive any errors

Returns
  The value of the parsed date/time

See also
  udat_format

Stable:
  ICU 2.0

## ◆ udat_parseCalendar()

U_CAPI void udat_parseCalendar | ( | const UDateFormat * | format,
|  | UCalendar * | calendar,
|  | const UChar * | text,
|  | int32_t | textLength,
|  | int32_t * | parsePos,
|  | UErrorCode * | status
| ) |  |

Parse a string into an date/time using a UDateFormat.

The date will be parsed using the conventions specified in `udat_open`.

Parameters

  format | The formatter to use.
  calendar | A calendar set on input to the date and time to be used for missing values in the date/time string being parsed, and set on output to the parsed date/time. When the calendar type is different from the internal calendar held by the UDateFormat instance, the internal calendar will be cloned to a work calendar set to the same milliseconds and time zone as this calendar parameter, field values will be parsed based on the work calendar, then the result (milliseconds and time zone) will be set in this calendar.
  text | The text to parse.
  textLength | The length of text, or -1 if null-terminated.
  parsePos | If not 0, on input a pointer to an integer specifying the offset at which to begin parsing. If not 0, on output the offset at which parsing ended.
  status | A pointer to an UErrorCode to receive any errors

See also
  udat_format

Stable:
  ICU 2.0

## ◆ udat_registerOpener()

U_CAPI void udat_registerOpener | ( | UDateFormatOpener | opener,
|  | UErrorCode * | status
| ) |  |

Register a provider factory.

Internal:
  Do not use. This API is for internal use only. ICU 49

## ◆ udat_set2DigitYearStart()

U_CAPI void udat_set2DigitYearStart | ( | UDateFormat * | fmt,
|  | UDate | d,
|  | UErrorCode * | status
| ) |  |

Set the year relative to which all 2-digit years will be interpreted.

For example, if the 2-digit start year is 2100, the year 99 will be interpreted as 2199.

Parameters

  fmt | The formatter to set.
  d | The year relative to which all 2-digit years will be interpreted.
  status | A pointer to an UErrorCode to receive any errors

See also
  udat_Set2DigitYearStart

Stable:
  ICU 2.0

## ◆ udat_setBooleanAttribute()

U_CAPI void udat_setBooleanAttribute | ( | UDateFormat * | fmt,
|  | UDateFormatBooleanAttribute | attr,
|  | UBool | newValue,
|  | UErrorCode * | status
| ) |  |

Set a boolean attribute associated with a UDateFormat.

An example of a boolean attribute is parse leniency control. If the formatter does not understand the attribute, the call is ignored.

Parameters

  fmt | The formatter to set.
  attr | The attribute to set; one of UDAT_PARSE_ALLOW_WHITESPACE or UDAT_PARSE_ALLOW_NUMERIC
  newValue | The new value of attr.
  status | A pointer to an UErrorCode to receive any errors

Stable:
  ICU 53

## ◆ udat_setCalendar()

U_CAPI void udat_setCalendar | ( | UDateFormat * | fmt,
|  | const UCalendar * | calendarToSet
| ) |  |

Set the UCalendar associated with an UDateFormat.

A UDateFormat uses a UCalendar to convert a raw value to, for example, the day of the week.

Parameters

  fmt | The formatter to set.
  calendarToSet | A pointer to an UCalendar to be used by fmt.

See also
  udat_setCalendar

Stable:
  ICU 2.0

## ◆ udat_setContext()

U_CAPI void udat_setContext | ( | UDateFormat * | fmt,
|  | UDisplayContext | value,
|  | UErrorCode * | status
| ) |  |

Set a particular UDisplayContext value in the formatter, such as UDISPCTX_CAPITALIZATION_FOR_STANDALONE.

Parameters

  fmt | The formatter for which to set a UDisplayContext value.
  value | The UDisplayContext value to set.
  status | A pointer to an UErrorCode to receive any errors

Stable:
  ICU 51

## ◆ udat_setLenient()

U_CAPI void udat_setLenient | ( | UDateFormat * | fmt,
|  | UBool | isLenient
| ) |  |

Specify whether an UDateFormat will perform lenient parsing.

With lenient parsing, the parser may use heuristics to interpret inputs that do not precisely match the pattern. With strict parsing, inputs must match the pattern.

Parameters

  fmt | The formatter to set
  isLenient | true if fmt should perform lenient parsing, false otherwise.

See also
  dat_isLenient

Stable:
  ICU 2.0

## ◆ udat_setNumberFormat()

U_CAPI void udat_setNumberFormat | ( | UDateFormat * | fmt,
|  | const UNumberFormat * | numberFormatToSet
| ) |  |

Set the UNumberFormat associated with an UDateFormat.

A UDateFormat uses a UNumberFormat to format numbers within a date, for example the day number. This method also clears per field NumberFormat instances previously set by {

See also
  udat_setNumberFormatForField}

Parameters

  fmt | The formatter to set.
  numberFormatToSet | A pointer to the UNumberFormat to be used by fmt to format numbers.

See also
  udat_getNumberFormat
  udat_setNumberFormatForField

Stable:
  ICU 2.0

## ◆ udat_setSymbols()

U_CAPI void udat_setSymbols | ( | UDateFormat * | format,
|  | UDateFormatSymbolType | type,
|  | int32_t | symbolIndex,
|  | UChar * | value,
|  | int32_t | valueLength,
|  | UErrorCode * | status
| ) |  |

Set the symbols associated with an UDateFormat.

The symbols are what a UDateFormat uses to represent locale-specific data, for example month or day names.

Parameters

  format | The formatter to set
  type | The type of symbols to set. One of UDAT_ERAS, UDAT_MONTHS, UDAT_SHORT_MONTHS, UDAT_WEEKDAYS, UDAT_SHORT_WEEKDAYS, UDAT_AM_PMS, or UDAT_LOCALIZED_CHARS
  symbolIndex | The index of the symbol to set of type type.
  value | The new value
  valueLength | The length of value, or -1 if null-terminated
  status | A pointer to an UErrorCode to receive any errors

See also
  udat_getSymbols
  udat_countSymbols

Stable:
  ICU 2.0

## ◆ udat_toCalendarDateField()

U_CAPI UCalendarDateFields udat_toCalendarDateField | ( | UDateFormatField | field | ) |

Maps from a UDateFormatField to the corresponding UCalendarDateFields.

Note 1: Since the mapping is many-to-one, there is no inverse mapping.

Note 2: There is no UErrorCode parameter, so in case of error (UDateFormatField is unknown or has no corresponding UCalendarDateFields value), the function returns the current value of UCAL_FIELD_COUNT. However, that value may change from release to release and is consequently deprecated. For a future-proof runtime way of checking for errors: a) First save the value returned by the function when it is passed an invalid value such as "(UDateFormatField)-1". b) Then, to test for errors when passing some other UDateFormatField value, check whether the function returns that saved value.

Parameters

  field | the UDateFormatField.

Returns
  the UCalendarDateField. In case of error (UDateFormatField is unknown or has no corresponding UCalendarDateFields value) this will be the current value of UCAL_FIELD_COUNT, but that value may change from release to release. See Note 2 above.

Stable:
  ICU 4.4

## ◆ udat_toPattern()

U_CAPI int32_t udat_toPattern | ( | const UDateFormat * | fmt,
|  | UBool | localized,
|  | UChar * | result,
|  | int32_t | resultLength,
|  | UErrorCode * | status
| ) |  |

Extract the pattern from a UDateFormat.

The pattern will follow the pattern syntax rules.

Parameters

  fmt | The formatter to query.
  localized | true if the pattern should be localized, false otherwise.
  result | A pointer to a buffer to receive the pattern.
  resultLength | The maximum size of result.
  status | A pointer to an UErrorCode to receive any errors

Returns
  The total buffer size needed; if greater than resultLength, the output was truncated.

See also
  udat_applyPattern

Stable:
  ICU 2.0

## ◆ udat_toPatternRelativeDate()

U_CAPI int32_t udat_toPatternRelativeDate | ( | const UDateFormat * | fmt,
|  | UChar * | result,
|  | int32_t | resultLength,
|  | UErrorCode * | status
| ) |  |

Extract the date pattern from a UDateFormat set for relative date formatting.

The pattern will follow the pattern syntax rules.

Parameters

  fmt | The formatter to query.
  result | A pointer to a buffer to receive the pattern.
  resultLength | The maximum size of result.
  status | A pointer to a UErrorCode to receive any errors

Returns
  The total buffer size needed; if greater than resultLength, the output was truncated.

See also
  udat_applyPatternRelative

Internal:
  Do not use. This API is for internal use only. ICU 4.2 technology preview

## ◆ udat_toPatternRelativeTime()

U_CAPI int32_t udat_toPatternRelativeTime | ( | const UDateFormat * | fmt,
|  | UChar * | result,
|  | int32_t | resultLength,
|  | UErrorCode * | status
| ) |  |

Extract the time pattern from a UDateFormat set for relative date formatting.

The pattern will follow the pattern syntax rules.

Parameters

  fmt | The formatter to query.
  result | A pointer to a buffer to receive the pattern.
  resultLength | The maximum size of result.
  status | A pointer to a UErrorCode to receive any errors

Returns
  The total buffer size needed; if greater than resultLength, the output was truncated.

See also
  udat_applyPatternRelative

Internal:
  Do not use. This API is for internal use only. ICU 4.2 technology preview

## ◆ udat_unregisterOpener()

U_CAPI UDateFormatOpener udat_unregisterOpener | ( | UDateFormatOpener | opener,
|  | UErrorCode * | status
| ) |  |

Un-Register a provider factory.

Internal:
  Do not use. This API is for internal use only. ICU 49