Conversion Specifications

The following conversion specifications are supported:

%%

Same as %.

%a

Locale's abbreviated weekday name.

%A

Locale's full weekday name.

%b

Locale's abbreviated month name.

%B

Locale's full month name.

%c

Locale's appropriate date and time representation.

%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. If used without the %y specifier, this format specifier will assume the current year offset in whichever century is specified. The only valid years are between 1902-2037.

%d

day of month [01,31]; leading zero is permitted but not required.

%D

Date as %m/%d/%y.

%e

Same as %d.

%h

Locale's abbreviated month name.

%H

Hour (24-hour clock) [0,23]; leading zero is permitted but not required.

%I

Hour (12-hour clock) [1,12]; leading zero is permitted but not required.

%j

Day number of the year [1,366]; leading zeros are permitted but not required.

%m

Month number [1,12]; leading zero is permitted but not required.

%M

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

%n

Any white space.

%p

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

%r

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

%R

Time as %H:%M.

%S

Seconds [0,61]; leading zero is permitted but not required. 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

Any white space.

%T

Time as %H:%M:%S.

%U

Week number of the year as a decimal number [0,53], with Sunday as the first day of the week; leading zero is permitted but not required.

%w

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

%W

Week number of the year as a decimal number [0,53], with Monday as the first day of the week; leading zero is permitted but not required.

%x

Locale's appropriate date representation.

%X

Locale's appropriate time representation.

%y

Year within century. When a century is not otherwise specified, values in the range 69-99 refer to years in the twentieth century (1969 to 1999 inclusive); values in the range 00-68 refer to years in the twenty-first century (2000 to 2068 inclusive).

%Y

Year, including the century (for example, 1993).

%Z

Time zone name or no characters if no time zone exists.

Modified Conversion Specifications

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

%Ec

Locale's alternative appropriate date and time representation.

%EC

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

%Ex

Locale's alternative date representation.

%EX

Locale's alternative time representation.

%Ey

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

%EY

Full alternative year representation.

%Od

Day of the month using the locale's alternative numeric symbols; leading zeros are permitted but not required.

%Oe

Same as %Od.

%OH

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

%OI

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

%Om

Month using the locale's alternative numeric symbols.

%OM

Minutes using the locale's alternative numeric symbols.

%OS

Seconds using the locale's alternative numeric symbols.

%OU

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

%Ow

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

%OW

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

%Oy

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

Internal Format Conversion

The following rules are applied for converting the input specification into the internal format:

• If only the weekday is given, today is assumed if the given day is equal to the current day and next week if it is less.
• If only the month is given, the current month is assumed if the given month is equal to the current month and next year if it is less and no year is given. (The first day of month is assumed if no day is given.)
• If only the year is given, the values of the tm_mon, tm_mday, tm_yday, tm_wday, and tm_isdst members of the returned tm structure are not specified.
• If the century is given, but the year within the century is not given, the current year within the century is assumed.
• If no hour, minute, and second are given, the current hour, minute, and second are assumed.
• If no date is given, today is assumed if the given hour is greater than the current hour and tomorrow is assumed if it is less.

General Specifications

A conversion specification that is an ordinary character is executed by scanning the next character from the buffer. If the character scanned from the buffer differs from the one comprising the conversion specification, the specification fails, and the differing and subsequent characters remain unscanned.

A series of conversion specifications composed of ‘%n’, ‘%t’, white space characters, or any combination is executed by scanning up to the first character that is not white space (which remains unscanned), or until no more characters can be scanned.

Any other conversion specification is executed by scanning characters until a character matching the next conversion specification is scanned, or until no more characters can be scanned. These characters, except the one matching the next conversion specification, are then compared to the locale values associated with the conversion specifier. If a match is found, values for the appropriate tm structure members are set to values corresponding to the locale information. If no match is found, getdate() fails and no more characters are scanned.

The month names, weekday names, era names, and alternative numeric symbols can consist of any combination of upper and lower case letters. The user can request that the input date or time specification be in a specific language by setting the LC_TIME category using setlocale(3).