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 GetDateFormat

The GetDateFormat function formats a date as a date string for a specified locale. The function formats either a specified date or the local system date.

int GetDateFormat(
  LCID Locale,               // locale
  DWORD dwFlags,             // options
  CONST SYSTEMTIME *lpDate,  // date
  LPCTSTR lpFormat,          // date format
  LPTSTR lpDateStr,          // formatted string buffer
  int cchDate                // size of buffer
);

Parameters

Locale
[in] Specifies the locale for which the date string is to be formatted. If lpFormat is NULL, the function formats the string according to the date format for this locale. If lpFormat is not NULL, the function uses the locale only for information not specified in the format picture string (for example, the locale's day and month names). This parameter can be a locale identifier created by the MAKELCID macro, or one of the following predefined values. Value Meaning LOCALE_SYSTEM_DEFAULT Default system locale. LOCALE_USER_DEFAULT Default user locale.
dwFlags
[in] Specifies various function options. If lpFormat is non-NULL, this parameter must be zero. If lpFormat is NULL, you can specify a combination of the following values. Value Meaning LOCALE_NOUSEROVERRIDE If set, the function formats the string using the system default–date format for the specified locale. If not set, the function formats the string using any user overrides to the locale's default–date format. LOCALE_USE_CP_ACP Uses the system ANSI code page for string translation instead of the locale's code page. DATE_SHORTDATE Uses the short date format. This is the default. This value cannot be used with DATE_LONGDATE or DATE_YEARMONTH. DATE_LONGDATE Uses the long date format. This value cannot be used with DATE_SHORTDATE or DATE_YEARMONTH. DATE_YEARMONTH Uses the year/month format. This value cannot be used with DATE_SHORTDATE or DATE_LONGDATE. DATE_USE_ALT_CALENDAR Uses the alternate calendar, if one exists, to format the date string. If this flag is set, the function uses the default format for that alternate calendar, rather than using any user overrides. The user overrides will be used only in the event that there is no default format for the specified alternate calendar. DATE_LTRREADING Adds marks for left-to-right reading layout. This value cannot be used with DATE_RTLREADING. DATE_RTLREADING Adds marks for right-to-left reading layout. This value cannot be used with DATE_LTRREADING If you do not specify either DATE_YEARMONTH, DATE_SHORTDATE, or DATE_LONGDATE, and lpFormat is NULL, then DATE_SHORTDATE is the default.
lpDate
[in] Pointer to a SYSTEMTIME structure that contains the date information to be formatted. If this pointer is NULL, the function uses the current local system date.
lpFormat
[in] Pointer to a format picture string that is used to form the date string. The format picture string must be zero terminated. If lpFormat is NULL, the function uses the date format of the specified locale. Use the following elements to construct a format picture string. If you use spaces to separate the elements in the format string, these spaces will appear in the same location in the output string. The letters must be in uppercase or lowercase as shown in the table (for example, "MM" not "mm"). Characters in the format string that are enclosed in single quotation marks will appear in the same location and unchanged in the output string. Picture Meaning

        d       Day of month as digits with no leading zero for single-digit days. 
        dd      Day of month as digits with leading zero for single-digit days. 
        ddd     Day of week as a three-letter abbreviation. The function uses the LOCALE_SABBREVDAYNAME value associated with the specified locale. 
        dddd    Day of week as its full name. The function uses the LOCALE_SDAYNAME value associated with the specified locale. 
        M       Month as digits with no leading zero for single-digit months. 
        MM      Month as digits with leading zero for single-digit months. 
        MMM     Month as a three-letter abbreviation. The function uses the LOCALE_SABBREVMONTHNAME value associated with the specified locale. 
        MMMM    Month as its full name. The function uses the LOCALE_SMONTHNAME value associated with the specified locale. 
        y       Year as last two digits, but with no leading zero for years less than 10. 
        yy      Year as last two digits, but with leading zero for years less than 10. 
        yyyy    Year represented by full four digits. 
        gg      Period/era string. The function uses the CAL_SERASTRING value associated with the specified locale. This element is ignored if the date to be formatted does not have an associated era or period string. 

For example, to get the date string "Wed, Aug 31 94"
use the following picture string:
"ddd',' MMM dd yy"
lpDateStr
[out] Pointer to a buffer that receives the formatted date string.
cchDate
[in] Specifies the size, in TCHARs, of the lpDateStr buffer. If cchDate is zero, the function returns the number of bytes or characters required to hold the formatted date string, and the buffer pointed to by lpDateStr is not used.

Return Values

If the function succeeds, the return value is the number of TCHARs written to the lpDateStr buffer, or if the cchDate parameter is zero, the number of bytes or characters required to hold the formatted date string. The count includes the terminating null. If the function fails, the return value is zero. To get extended error information, call GetLastError. GetLastError may return one of the following error codes:
• ERROR_INSUFFICIENT_BUFFER
• ERROR_INVALID_FLAGS
• ERROR_INVALID_PARAMETER

Remarks

The earliest date supported by this function is January 1, 1601. The day name, abbreviated day name, month name, and abbreviated month name are all localized based on the locale identifier. The date values in the SYSTEMTIME structure pointed to by lpDate must be valid. The function checks each of the date values: year, month, day, and day of week. If the day of the week is incorrect, the function uses the correct value, and returns no error. If any of the other date values are outside the correct range, the function fails, and sets the last-error to ERROR_INVALID_PARAMETER. The function ignores the time portions of the SYSTEMTIME structure pointed to by lpDate: wHour, wMinute, wSecond, and wMilliseconds. If the lpFormat parameter is a bad format string, no errors are returned. The function simply forms the best date string that it can. For example, the only year pictures that are valid are L"yyyy" and L"yy" (the 'L' indicates a Unicode (16-bit characters) string). If L"y" is passed in, the function assumes L"yy". If L"yyy" is passed in, the function assumes L"yyyy". If more than 4 date (L"dddd") or 4 month (L"MMMM") pictures are passed in, then the function defaults to L"dddd" or L"MMMM". Any text that should remain in its exact form in the date string should be enclosed within single quotation marks in the date format picture. The single quotation mark may also be used as an escape character to allow the single quotation mark itself to be displayed in the date string. However, the escape sequence must be enclosed within two single quotation marks. For example, to display the date as "May '93", the format string would be: L"MMMM 'yy" The first and last single quotation marks are the enclosing quotation marks. The second and third single quotation marks are the escape sequence to allow the single quotation mark to be displayed before the century. When the date picture contains a numeric form of the day (either d or dd) followed by the full month name (MMMM), the genitive form of the month name is returned in the date string. To obtain the default short and long date format without performing any actual formatting, use the GetLocaleInfo function with the LOCALE_SSHORTDATE or LOCALE_SLONGDATE parameter. To get the date format for an alternate calendar, use GetLocaleInfo with the LOCALE_IOPTIONALCALENDAR parameter. To get the date format for a particular calendar, use GetCalendarInfo. Also, to return all of the date formats for a particular calendar, you can use EnumCalendarInfo or EnumDateFormatsEx. Windows 2000 or later: The ANSI version of this function will fail if it is used with a Unicode-only LCID. See Language Identifiers.

= Requirements =

Windows NT/2000 or later: Requires Windows NT 3.5 or later. Windows 95/98/Me: Requires Windows 95 or later. Header: Declared in Winnls.h; include Windows.h. Library: Use Kernel32.lib. Unicode: Implemented as Unicode and ANSI versions on Windows NT/2000.

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Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time