%C

Locale's date and time representation as produced by date(1).

%C

Century number (the year divided by 100 and truncated to an integer as a decimal number [1,99]); single digits are preceded by 0; see standards(5).

%d

Day of month [1,31]; single digits are preceded by 0.

%D

Date as %m/%d/%y.

%e

Day of month [1,31]; single digits are preceded by a space.

%g

Week-based year within century [00,99].

%G

Week-based year, including the century [0000,9999].

%h

Locale's abbreviated month name.

%H

Hour (24-hour clock) [0,23]; single digits are preceded by 0.

%I

Hour (12-hour clock) [1,12]; single digits are preceded by 0.

%j

Day number of year [1,366]; single digits are preceded by 0.

%k

Hour (24-hour clock) [0,23]; single digits are preceded by a blank.

%l

Hour (12-hour clock) [1,12]; single digits are preceded by a blank.

%m

Month number [1,12]; single digits are preceded by 0.

%M

Minute [00,59]; leading 0 is permitted but not required.

%n

Insert a NEWLINE.

%p

Locale's equivalent of either a.m. or p.m.

%r

Appropriate time representation in 12-hour clock format with %p.

%R

Time as %H:%M.

%S

Seconds [00,61]; the range of values is [00,61] rather than [00,59] to allow for the occasional leap second and even more occasional double leap second.

%t

Insert a TAB.

%T

Time as %H:%M:%S.

%u

Weekday as a decimal number [1,7], with 1 representing Monday. See NOTES below.

%U

Week number of year as a decimal number [00,53], with Sunday as the first day of week 1.

%V

The ISO 8601 week number as a decimal number [01,53]. In the ISO 8601 week-based system, weeks begin on a Monday and week 1 of the year is the week that includes both January 4th and the first Thursday of the year. If the first Monday of January is the 2nd, 3rd, or 4th, the preceding days are part of the last week of the preceding year. See NOTES below.

%w

Weekday as a decimal number [0,6], with 0 representing Sunday.

%W

Week number of year as a decimal number [00,53], with Monday as the first day of week 1.

%x

Locale's appropriate date representation.

%X

Locale's appropriate time representation.

%y

Year within century [00,99].

%Y

Year, including the century (for example 1993).

%Z

Time zone name or abbreviation, or no bytes if no time zone information exists.

If a conversion specification does not correspond to any of the above or to any of the modified conversion specifications listed below, the behavior is undefined and 0 is returned.

The difference between %U and %W (and also between modified conversion specifications %OU and %OW) lies in which day is counted as the first of the week. Week number 1 is the first week in January starting with a Sunday for %U or a Monday for %W. Week number 0 contains those days before the first Sunday or Monday in January for %U and %W, respectively.

Some conversion specifications can be modified by the E and O modifiers to indicate that an alternate format or specification should be used rather than the one normally used by the unmodified conversion specification. If the alternate format or specification does not exist in the current locale, the behavior will be as if the unmodified specification were used.

%Ec

Locale's alternate appropriate date and time representation.

%EC

Name of the base year (period) in the locale's alternate representation.

%Eg

Offset from %EC of the week-based year in the locale's alternative representation.

%EG

Full alternative representation of the week-based year.

%Ex

Locale's alternate date representation.

%EX

Locale's alternate time representation.

%Ey

Offset from %EC (year only) in the locale's alternate representation.

%EY

Full alternate year representation.

%Od

Day of the month using the locale's alternate numeric symbols.

%Oe

Same as %Od.

%Og

Week-based year (offset from %C) in the locale's alternate representation and using the locale's alternate numeric symbols.

%OH

Hour (24-hour clock) using the locale's alternate numeric symbols.

%OI

Hour (12-hour clock) using the locale's alternate numeric symbols.

%Om

Month using the locale's alternate numeric symbols.

%OM

Minutes using the locale's alternate numeric symbols.

%OS

Seconds using the locale's alternate numeric symbols.

%Ou

Weekday as a number in the locale's alternate numeric symbols.

%OU

Week number of the year (Sunday as the first day of the week) using the locale's alternate numeric symbols.

%Ow

Number of the weekday (Sunday=0) using the locale's alternate numeric symbols.

%OW

Week number of the year (Monday as the first day of the week) using the locale's alternate numeric symbols.

%Oy

Year (offset from %C) in the locale's alternate representation and using the locale's alternate numeric symbols.

By default, the output of strftime(), cftime(), and ascftime() appear in U.S. English. The user can request that the output of strftime(), cftime(), or ascftime() be in a specific language by setting the LC_TIME category using setlocale().

Local time zone information is used as though tzset(3C) were called.

The following example illustrates the use of strftime() for the POSIX locale. It shows what the string in str would look like if the structure pointed to by tmptr contains the values corresponding to Thursday, August 28, 1986 at 12:44:36.

strftime (str, strsize, "%A %b %d %j", tmptr)

This results in str containing "Thursday Aug 28 240".