'\" t
.TH "STRFTIME" "3" "01/19/2023" "newlib" "Time Functions (time.h)"
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" .nh
.\" .ad l
.\" .SH "NAME"
.\" strftime, strftime_l \- convert date and time to a formatted string
.\" .SH "SYNOPSIS"
.\" .sp
.\" .ft B
.\" .nf
.\" #include <time\&.h>
.\" .fi
.\" .ft
.\" .HP \w'size_t\ strftime('u
.\" .BI "size_t strftime(char\ *restrict\ " "s" ", size_t\ " "maxsize" ", const\ char\ *restrict\ " "format" ", const\ struct\ tm\ *restrict\ " "timp" ");"
.\" .HP \w'size_t\ strftime_l('u
.\" .BI "size_t strftime_l(char\ *restrict\ " "s" ", size_t\ " "maxsize" ", const\ char\ *restrict\ " "format" ", const\ struct\ tm\ *restrict\ " "timp" ", locale_t\ " "locale" ");"
.SH "DESCRIPTION"
.PP
.\" strftime
.\" converts a
.\" struct tm
.\" representation of the time (at
.\" \fItimp\fR) into a null\-terminated string, starting at
.\" \fIs\fR
.\" and occupying no more than
.\" \fImaxsize\fR
.\" characters\&.
.PP
.\" strftime_l
.\" is like
.\" strftime
.\" but creates a string in a format as expected in locale
.\" \fIlocale\fR\&. If
.\" \fIlocale\fR
.\" is LC_GLOBAL_LOCALE or not a valid locale object, the behaviour is undefined\&.
.PP
.\" You control the format of the output using the string at
.\" \fIformat\fR\&.
.\" *\fIformat\fR
.\" can contain two kinds of specifications: text to be copied literally into the formatted string, and time conversion specifications\&. Time conversion specifications are two\- and three\-character sequences beginning with `%\*(Aq (use `%%\*(Aq to include a percent sign in the output)\&. Each defined conversion specification selects only the specified field(s) of calendar time data from
.\" *\fItimp\fR, and converts it to a string in one of the following ways:
.PP
.TS
tab(:);
l lx.
T{
%a
T}:T{
The abbreviated weekday name according to the current locale\&. [tm_wday]
T}
\&
T{
%A
T}:T{
The full weekday name according to the current locale\&. In the default "C" locale, one of `Sunday\*(Aq, `Monday\*(Aq, `Tuesday\*(Aq, `Wednesday\*(Aq, `Thursday\*(Aq, `Friday\*(Aq, `Saturday\*(Aq\&. [tm_wday]
T}
\&
T{
%b
T}:T{
The abbreviated month name according to the current locale\&. [tm_mon]
T}
\&
T{
%B
T}:T{
The full month name according to the current locale\&. In the default "C" locale, one of `January\*(Aq, `February\*(Aq, `March\*(Aq, `April\*(Aq, `May\*(Aq, `June\*(Aq, `July\*(Aq, `August\*(Aq, `September\*(Aq, `October\*(Aq, `November\*(Aq, `December\*(Aq\&. [tm_mon]
T}
\&
T{
%c
T}:T{
The preferred date and time representation for the current locale\&. [tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year, tm_wday]
T}
\&
T{
%C
T}:T{
The century, that is, the year divided by 100 then truncated\&. For 4\-digit years, the result is zero\-padded and exactly two characters; but for other years, there may a negative sign or more digits\&. In this way, `%C%y\*(Aq is equivalent to `%Y\*(Aq\&. [tm_year]
T}
\&
T{
%d
T}:T{
The day of the month, formatted with two digits (from `01\*(Aq to `31\*(Aq)\&. [tm_mday]
T}
\&
T{
%D
T}:T{
A string representing the date, in the form `"%m/%d/%y"\*(Aq\&. [tm_mday, tm_mon, tm_year]
T}
\&
T{
%e
T}:T{
The day of the month, formatted with leading space if single digit (from `1\*(Aq to `31\*(Aq)\&. [tm_mday]
T}
\&
T{
%Ex
T}:T{
In some locales, the E modifier selects alternative representations of certain modifiers
x\&. In newlib, it is ignored, and treated as %x\&.
T}
\&
T{
%F
T}:T{
A string representing the ISO 8601:2000 date format, in the form `"%Y\-%m\-%d"\*(Aq\&. [tm_mday, tm_mon, tm_year]
T}
\&
T{
%g
T}:T{
The last two digits of the week\-based year, see specifier %G (from `00\*(Aq to `99\*(Aq)\&. [tm_year, tm_wday, tm_yday]
T}
\&
T{
%G
T}:T{
The week\-based year\&. In the ISO 8601:2000 calendar, week 1 of the year includes January 4th, and begin on Mondays\&. Therefore, if January 1st, 2nd, or 3rd falls on a Sunday, that day and earlier belong to the last week of the previous year; and if December 29th, 30th, or 31st falls on Monday, that day and later belong to week 1 of the next year\&. For consistency with %Y, it always has at least four characters\&. Example: "%G" for Saturday 2nd January 1999 gives "1998", and for Tuesday 30th December 1997 gives "1998"\&. [tm_year, tm_wday, tm_yday]
T}
\&
T{
%h
T}:T{
Synonym for "%b"\&. [tm_mon]
T}
\&
T{
%H
T}:T{
The hour (on a 24\-hour clock), formatted with two digits (from `00\*(Aq to `23\*(Aq)\&. [tm_hour]
T}
\&
T{
%I
T}:T{
The hour (on a 12\-hour clock), formatted with two digits (from `01\*(Aq to `12\*(Aq)\&. [tm_hour]
T}
\&
T{
%j
T}:T{
The count of days in the year, formatted with three digits (from `001\*(Aq to `366\*(Aq)\&. [tm_yday]
T}
\&
T{
%k
T}:T{
The hour (on a 24\-hour clock), formatted with leading space if single digit (from `0\*(Aq to `23\*(Aq)\&. Non\-POSIX extension (c\&.p\&. %I)\&. [tm_hour]
T}
\&
T{
%l
T}:T{
The hour (on a 12\-hour clock), formatted with leading space if single digit (from `1\*(Aq to `12\*(Aq)\&. Non\-POSIX extension (c\&.p\&. %H)\&. [tm_hour]
T}
\&
T{
%m
T}:T{
The month number, formatted with two digits (from `01\*(Aq to `12\*(Aq)\&. [tm_mon]
T}
\&
T{
%M
T}:T{
The minute, formatted with two digits (from `00\*(Aq to `59\*(Aq)\&. [tm_min]
T}
\&
T{
%n
T}:T{
A newline character (`\en\*(Aq)\&.
T}
\&
T{
%Ox
T}:T{
In some locales, the O modifier selects alternative digit characters for certain modifiers
x\&. In newlib, it is ignored, and treated as %x\&.
T}
\&
T{
%p
T}:T{
Either `AM\*(Aq or `PM\*(Aq as appropriate, or the corresponding strings for the current locale\&. [tm_hour]
T}
\&
T{
%P
T}:T{
Same as \*(Aq%p\*(Aq, but in lowercase\&. This is a GNU extension\&. [tm_hour]
T}
\&
T{
%q
T}:T{
Quarter of the year (from `1\*(Aq to `4\*(Aq), with January starting the first quarter\&. This is a GNU extension\&. [tm_mon]
T}
\&
T{
%r
T}:T{
Replaced by the time in a\&.m\&. and p\&.m\&. notation\&. In the "C" locale this is equivalent to "%I:%M:%S %p"\&. In locales which don\*(Aqt define a\&.m\&./p\&.m\&. notations, the result is an empty string\&. [tm_sec, tm_min, tm_hour]
T}
\&
T{
%R
T}:T{
The 24\-hour time, to the minute\&. Equivalent to "%H:%M"\&. [tm_min, tm_hour]
T}
\&
T{
%s
T}:T{
The time elapsed, in seconds, since the start of the Unix epoch at 1970\-01\-01 00:00:00 UTC\&.
T}
\&
T{
%S
T}:T{
The second, formatted with two digits (from `00\*(Aq to `60\*(Aq)\&. The value 60 accounts for the occasional leap second\&. [tm_sec]
T}
\&
T{
%t
T}:T{
A tab character (`\et\*(Aq)\&.
T}
\&
T{
%T
T}:T{
The 24\-hour time, to the second\&. Equivalent to "%H:%M:%S"\&. [tm_sec, tm_min, tm_hour]
T}
\&
T{
%u
T}:T{
The weekday as a number, 1\-based from Monday (from `1\*(Aq to `7\*(Aq)\&. [tm_wday]
T}
\&
T{
%U
T}:T{
The week number, where weeks start on Sunday, week 1 contains the first Sunday in a year, and earlier days are in week 0\&. Formatted with two digits (from `00\*(Aq to `53\*(Aq)\&. See also
%W\&. [tm_wday, tm_yday]
T}
\&
T{
%V
T}:T{
The week number, where weeks start on Monday, week 1 contains January 4th, and earlier days are in the previous year\&. Formatted with two digits (from `01\*(Aq to `53\*(Aq)\&. See also
%G\&. [tm_year, tm_wday, tm_yday]
T}
\&
T{
%v
T}:T{
A string representing the BSD/OSX/Ruby VMS/Oracle date format, in the form "%e\-%b\-%Y"\&. Non\-POSIX extension\&. [tm_mday, tm_mon, tm_year]
T}
\&
T{
%w
T}:T{
The weekday as a number, 0\-based from Sunday (from `0\*(Aq to `6\*(Aq)\&. [tm_wday]
T}
\&
T{
%W
T}:T{
The week number, where weeks start on Monday, week 1 contains the first Monday in a year, and earlier days are in week 0\&. Formatted with two digits (from `00\*(Aq to `53\*(Aq)\&. [tm_wday, tm_yday]
T}
\&
T{
%x
T}:T{
Replaced by the preferred date representation in the current locale\&. In the "C" locale this is equivalent to "%m/%d/%y"\&. [tm_mon, tm_mday, tm_year]
T}
\&
T{
%X
T}:T{
Replaced by the preferred time representation in the current locale\&. In the "C" locale this is equivalent to "%H:%M:%S"\&. [tm_sec, tm_min, tm_hour]
T}
\&
T{
%y
T}:T{
The last two digits of the year (from `00\*(Aq to `99\*(Aq)\&. [tm_year] (Implementation interpretation: always positive, even for negative years\&.)
T}
\&
T{
%Y
T}:T{
The full year, equivalent to
%C%y\&. It will always have at least four characters, but may have more\&. The year is accurate even when tm_year added to the offset of 1900 overflows an int\&. [tm_year]
T}
\&
T{
%z
T}:T{
The offset from UTC\&. The format consists of a sign (negative is west of Greewich), two characters for hour, then two characters for minutes (\-hhmm or +hhmm)\&. If tm_isdst is negative, the offset is unknown and no output is generated; if it is zero, the offset is the standard offset for the current time zone; and if it is positive, the offset is the daylight savings offset for the current timezone\&. The offset is determined from the TZ environment variable, as if by calling tzset()\&. [tm_isdst]
T}
\&
T{
%Z
T}:T{
The current time zone abbreviation\&. If tm_isdst is negative, no output is generated\&. Otherwise, the time zone abbreviation is based on the TZ environment variable, as if by calling tzset()\&. [tm_isdst]
T}
\&
T{
%%
T}:T{
A single character, `%\*(Aq\&.
T}
\&
.TE