%a

Abbreviated weekday name 

%A

Full weekday name 

%b

Abbreviated month name 

%B

Full month name 

%c

Date and time representation appropriate for locale 

%d

Day of month as decimal number (01 - 31)

%H

Hour in 24 hour format (00 - 23)

%I

Hour in 12 hour format (01 - 12)

%j

Day of year as decimal number (001 - 366)

%m

Month as decimal number (01 - 12)

%M

Minute as decimal number (00 - 59)

%p

Current locale's A.M./P.M. indicator for 12 hour clock 

%S

Second as decimal number (00 - 59)

%U

Week of year as decimal number, with Sunday as first day of week (00 - 53)

%w

Weekday as decimal number (0 - 6; Sunday is 0)

%W

Week of year as decimal number, with Monday as first day of week (00 - 53)

%x

Date representation for current locale 

%X

Time representation for current locale 

%y

Year without century, as decimal number (00 - 99)

%Y

Year with century, as decimal number 

%Z

Time-zone name or abbreviation; no characters if time zone is unknown 

%%

Percent sign