%a  Abbreviated weekday name  Sat 
%A  Full weekday name  Saturday 
%b  Abbreviated month name  Oct 
%B  Full month name  October 
%C  Century number (year/100) as a 2digit integer  20 
%d  Day of the month, padded to 2 digits (0131)  21 
%D  Equivalent to %m/%d/%y in enUS  10/21/17 
%e  Day of the month, padded with a leading space for single digit values (131)  21 
%F  Equivalent to %Y%m%d (the ISO 8601 date format)  20171021 
%h  Equivalent to %b (abbreviated month name)  Oct 
%H  The hour (24hour clock), padded to 2 digits (0023)  14 
%I  The hour (12hour clock), padded to 2 digits (0112)  02 
%j  Day of the year, padded to 3 digits (001366)  294 
%k  The hour (24hour clock), padded with a leading space for single digit values (023)  14 
%l  The hour (12hour clock), padded with a leading space for single digit values (112)  2 
%m  The month, padded to 2 digits (0112)  10 
%n  Newline character 

%M  The minute, padded to 2 digits (0059)  30 
%p  "AM" or "PM"  PM 
%P  "am" or "PM"  pm 
%r  Equivalent to %I:%M:%S %p (time in a.m. or p.m. notation)  02:30:48 PM 
%R  Equivalent to %H:%M (time in 24hour notation)  14:30 
%s  N umber of seconds since the Epoch (19700101 00:00:00 +0000), UTC  1508589048 
%S  The second, padded to 2 digits (0060)  48 
%t  Tab character  
%T  Equivalent to %H:%M:%S (time in 24hour notation)  14:30:48 
%u  Weekday, Monday being 1 (17)  6 
%U  Week number of the year, Sunday as the first day of the week, padded to 2 digits (0053)  42 
%w  Weekday, Sunday being 0 (06)  6 
%W  Week number of the year, Monday as the first day of the week, padded to 2 digits (0053)  42 
%y  The year without the century (0099)  17 
%Y  The year with the century  2017 
%z  The +hhmm or hhmm numeric timezone (that is, the hour and minute offset from UTC)  +0200 
%Z  The time zone name, replaced with an empty string if it is not found  CEST 
%%  A % sign  % 