%%      PERCENT
    %a      day of the week abbr
    %A      day of the week
    %b      month abbr
    %B      month
    %c      ctime format: Sat Nov 19 21:05:57 1994
    %d      numeric day of the month
    %e      DD
    %D      MM/DD/YY
    %h      month abbr
    %H      hour, 24 hour clock, leading 0's)
    %I      hour, 12 hour clock, leading 0's)
    %j      day of the year
    %k      hour
    %l      hour, 12 hour clock
    %m      month number, starting with 1
    %M      minute, leading 0's
    %n      NEWLINE
    %o      ornate day of month -- "1st", "3rd", etc.
    %p      AM or PM 
    %r      time format: 09:05:57 PM
    %R      time format: 21:05
    %s      seconds since the Epoch, UCT
    %S      seconds, leading 0's
    %t      TAB
    %T      time format: 21:05:57
    %U      week number, Sunday as first day of week
    %w      day of the week, numerically, Sunday == 0
    %W      week number, Monday as first day of week
    %x      date format: 11/19/94
    %X      time format: 21:05:57
    %y      year (2 digits)
    %Y      year (4 digits)
    %Z      timezone in ascii. eg: PST. Not implemement.
    %z      timezone in format -/+0000