Home Contents | # datetime:format | Date/Time | Core4 Lua Commands

## SYNOPSIS

str = datetime:format(fmt)

## DESCRIPTION

Formats the date/time stored in datetime according to the format specification in fmt. This function makes use of the C-library function strftime() and uses the same format specification.

The format string consists of zero or more conversion specifications and ordinary characters. All ordinary characters are copied directly into the result. A conversion specification consists of a percent sign ‘%’ and one other character.

Each conversion specification is replaced by the characters as follows which are then copied into the result.

%A | is replaced by the locale’s full weekday name.
%a | is replaced by the locale’s abbreviated weekday name.
%B | is replaced by the locale’s full month name.
%b or %h | is replaced by the locale’s abbreviated month name.
%C | is replaced by the century (a year divided by 100 and truncated to an integer) as a decimal number (00-99).
%c | is replaced by the locale’s appropriate date and time representation.
%D | is replaced by the date in the format “%m/%d/%y”.
%d | is replaced by the day of the month as a decimal number (01-31).
%e | is replaced by the day of month as a decimal number (1-31); single digits are preceded by a blank.
%F | is replaced by the date in the format “%Y-%m-%d”.
%G | is replaced by the ISO 8601 year with century as a decimal number.
%g | is replaced by the ISO 8601 year without century as a decimal number (00-99).
%H | is replaced by the hour (24-hour clock) as a decimal number (00-23).
%I | is replaced by the hour (12-hour clock) as a decimal number (01-12).
%j | is replaced by the day of the year as a decimal number (001-366).
%k | is replaced by the hour (24-hour clock) as a decimal number (0-23); single digits are preceded by a blank.
%l | is replaced by the hour (12-hour clock) as a decimal number (1-12); single digits are preceded by a blank.
%M | is replaced by the minute as a decimal number (00-59).
%m | is replaced by the month as a decimal number (01-12).
%n | is replaced by a newline.
%p | is replaced by the locale’s equivalent of either “AM” or “PM”.
%P | is replaced by the locale’s equivalent of either “am” or “pm”.
%R | is replaced by the time in the format “%H:%M”.
%r | is replaced by the locale’s representation of 12-hour clock time using AM/PM notation.
%S | is replaced by the second as a decimal number (00-61). The range of seconds is (00-61) instead of (00-59) to allow for the periodic occurrence of leap seconds and double leap seconds.
%s | is replaced by the number of seconds since midnight of 1970-01-01, UTC.
%T | is replaced by the time in the format “%H:%M:%S”.
%t | is replaced by a tab.
%U | is replaced by the week number of the year (Sunday as the first day of the week) as a decimal number (00-53).
%u | is replaced by the weekday (Monday as the first day of the week) as a decimal number (1-7).
%V | is replaced by the week number of the year (Monday as the first day of the week) as a decimal number (01-53). If the week containing January 1 has four or more days in the new year, then it is week 1; otherwise it is week 53 of the previous year, and the next week is week 1.
%v | is replaced by the date in the format “%e-%b-%Y”.
%W | is replaced by the week number of the year (Monday as the first day of the week) as a decimal number (00-53).
%w | is replaced by the weekday (Sunday as the first day of the week) as a decimal number (0-6).
%X | is replaced by the locale’s appropriate time representation.
%x | is replaced by the locale’s appropriate date representation.
%Y | is replaced by the year with century as a decimal number.
%y | is replaced by the year without century as a decimal number (00-99).
%Z | is replaced by the time zone name, or by the empty string if this is not determinable.
%z | is replaced by the offset from UTC in the format “+HHMM” or “-HHMM” as appropriate, with positive values representing locations east of Greenwich, or by the empty string if this is not determinable.
%% | is replaced by ‘%’.
%+ | is a shortcut for “%a %b %e %T %Z %Y”

## RETURN VALUE

The formatted value as a string.

## ERRORS

Raises an error if datetime is not a datetime instance.

## EXAMPLE

> >
t = clock.newDateTime(1990, 12, 25, 12, 34, 56) print(t:format("%a, %d %b %Y %H:%M:%S"))
Sun, 25 Dec 1990 12:34:56

## NOTES

The format documentation is courtesy of the OpenBSD strftime(3) man-page.

## SEE ALSO

clock.currentDateTime, clock.newDateTime, clock.setDateTime, clock.tzget, clock.tzset, datetime(), datetime:addDays, datetime:addMonths, datetime:addSecs, datetime:addYears, datetime:base90, datetime:toTime_t, datetime:date, datetime:day, datetime:daysTo, datetime:hour, datetime:isNull, datetime:isValid, datetime:isdst, datetime:minute, datetime:month, datetime:msec, datetime:offset, datetime:second, datetime:secsTo, datetime:set, datetime:setBase90, datetime:setTime_t, datetime:time, datetime:toLocal, datetime:toUTC, datetime:year, datetime:zone, tostring(datetime)