%a  :  abbreviated weekday name
%A  :  Full weekday name
%b  :  abbreviated month name
%B  :  Full month name
%c  :  standard date and time string
%C  :  last two digits of the year
%d  :  day of month as a decimal (e.g 1 to 31)
%H  :  hour (0 - 23)
%I  :  hour (1 - 12)
%j  :  day of year as a decimal ( 1 to 366)
%m  :  month as a decimal ( 1 to 12)
%M  :  minute as a decimal ( 0 to 59 )
%p  :  am or pm
%S  :  second as a decimal ( 0 to 60 )
%U  :  week of the year ( 0 to 53 ) Sunday is first day
%w  :  weekday as a decimal (0 is Sunday)
%W  :  week of the year ( 0 to 53 ) Monday is first day
%x  :  standard date string
%X  :  standard time string
%Y  :  year including century as a decimal
%Z  :  time zone name
%%  :  percent sign