asctime()

clock

reference to the clock or timer whose value should be converted to a character string The clock is most commonly time().

format

optional format symbol for the asctime() output string. For some common field symbols, see the following table for Format Symbols for asctime()

Default 
24-character string with the following format: 
Sun Sep 16 01:03:52 1973

%%

allows you to use a percent sign (%) in the format of a date string

%a

locale's abbreviated name of the day of week

%A

locale's full name of the day of week

%b

locale's abbreviated name of the month

%B

locale's full name of the month

%c

locale's appropriate date and time representation

%C

data and time as %c

%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

%h

locale's abbreviated name of the month

%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 of year [1,366]; single digits are preceded by 0

%k

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

%l

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

%m

month as a decimal number [1,12]; single digits are preceded by 0

%M

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

%n

insert a new line

%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 [0,61]

%t

insert a tab

%T

time as %H:%M:%S

%u

day of week as a decimal number [1,7], with 1 representing Monday

%U

week of the year as a decimal number [0,53], with Sunday as the first day of week 1

%V

week of the year as a decimal number [01,53], with Monday as the first day of the week If the week containing 1 January has four or more days in the new year, it is considered week 1; otherwise, it is week 53 of the previous year, and the next week is week 1.

%w

day of week as a decimal number [0,6], with 0 representing Sunday

%W

week of the year as a decimal number [0,53], 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 [0,99]

%Y

year, including the century (for example 1993)

%Z

abbreviated or full name of time zone, or no bytes if no information of the time zone exists

%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

alternative representation of the year in full

%Od

day of the month using the locale's alternative numeric symbols

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

%Ow

day of week (Sunday=0) using the locale's alternative numeric symbols

%OW

week 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