Date and Time Formatting

The Date and Time formatting functions are intended to provide a set of simple, cross platform functions that Mozilla developers can use to perform locale sensitive date and time formatting operations.

The caller first need to instanciate nsILocale.
FormatTime performs a locale sensitive date formatting operation on the time_t parameter. The formatted string is returned in nsString. The date/time string is formatted according to conventions of the given locale and the given selectors.
FormatTMTime performs a locale sensitive date formatting operation on the struct tm parameter. The formatted string is returned in nsString. The date/time string is formatted according to conventions of the given locale and the given selectors.

API

typedef enum {
    kDateFormatNone,                // do not include the date in the format string
    kDateFormatLong,                // provides the long date format for the given locale
    kDateFormatShort,               // provides the short date format for the given locale
    kDateFormatYearMonth,           // formats using only the year and month
    kDateFormatWeekday              // week day (e.g. Mon, Tue)
} nsDateFormatSelector;

typedef enum {
    kTimeFormatNone,                // don't include the time in the format string
    kTimeFormatSeconds,             // provides the time format with seconds in the given locale
    kTimeFormatNoSeconds,           // provides the time format without seconds in the given locale
    kTimeFormatSecondsForce24Hour, // forces the time format to use the 24 clock, regardless of the locale conventions
    kTimeFormatNoSecondsForce24Hour // forces the time format to use the 24 clock, regardless of the locale conventions
} nsTimeFormatSelector;

// Create a date/time format interface for an input locale.
//

class nsIDateTimeFormat : public nsISupports {

public:

// performs a locale sensitive date formatting operation on the time_t parameter
NS_IMETHOD FormatTime(nsILocale* locale,
                        const nsDateFormatSelector dateFormatSelector,
                        const nsTimeFormatSelector timeFormatSelector,
                        const time_t timetTime,
                        nsString& stringOut) = 0;

// performs a locale sensitive date formatting operation on the struct tm parameter
NS_IMETHOD FormatTMTime(nsILocale* locale,
                          const nsDateFormatSelector dateFormatSelector,
                          const nsTimeFormatSelector timeFormatSelector,
                          const struct tm* tmTime,
                          nsString& stringOut) = 0;
};

Example

Following example format a current time by using both FormatTime and FormatTMTime. Details omitted.

nsAutoString dateString;
time_t timetTime;

// create a nsILocale by nsILocaleFactory (see the spec or mozilla/intl/locale/test/nsLocaleTest.cpp)

// create an instance
res = nsRepository::CreateInstance(kDateTimeFormatCID, NULL, kIDateTimeFormatIID, (void**) &inst);

// get a current time
time(&timetTime);

// format by using FormatTime
res = inst->FormatTime(locale, kDateFormatShort, kTimeFormatSeconds, timetTime, dateString);

// format by using FormatTMTime
res = inst->FormatTMTime(locale, kDateFormatWeekday, kTimeFormatNoSecondsForce24Hour, localtime(&ltime), dateString);

Undecided (or unimplemented) issues

Input string is specifed as nsStrings, this may change (to whatever appropriate for XPIDL).