Ruby strftime

Year

%y

Year without a century

00..99

%Y

Year with century

2017

Month

%b

The abbreviated month name

Jan

%B

The full month name

January

%m

Month of the year

01..12

%-m

Month of the year

1..12

Day

%d

Day of the month

01..31

%e

Day of the month without leading zeroes

1..31

%j

Day of the year

001..366

%w

Day of the week. Sunday is 0

0..6

Hour

%H

Hour of the day, 24-hour clock

00..23

%I

Hour of the day, 12-hour clock

01..12

%k

Hour of the day, 24-hour clock w/o leading zeroes

0..23

%l

Hour of the day, 12-hour clock w/o leading zeroes

1..12

Minute & Second

%M

Minute of the hour

00..59

%p

Meridian indicator

AM or PM

%P

Meridian indicator

am or pm

%S

Second of the minute

00..60

Week

%U

Week number of the current year, starting with the first Sunday as the first day of the first week

00..53

%W

Week number of the current year, starting with the first Monday as the first day of the first week

00..53

%a

The abbreviated weekday name

Sun

%A

The full weekday name

Sunday

Time Zone

%Z

Time zone expressed as a UTC offset with hour-minute separator

+03:00

%z

Time zone expressed as a UTC offset

+0300

Predefined Formats

%c

The preferred local date and time representation

Fri May 12 18:54:56 2017

%x

Preferred representation for the date alone, no time

05/12/17

%X

Preferred representation for the time alone, no date

18:54:21

%%

Literal % character