"%a"    "Fri"                           abbreviated weekday name
  "%A"    "Friday"                        full weekday name
  "%b"    "Feb"                           abbreviated month name
  "%B"    "February"                      full month name
  "%c"    "Fri Feb  3 14:34:56 1984"      date and time ("%a %b %e %H:%M:%S %Y")
  "%C"    "19"                            two-digit year [00,99]
  "%d"    "03"                            month number [01,31]
  "%D"    "02/03/84"                      date as "%m/%d/%y"
  "%e"    " 3"                            month number [ 1,31]
  "%F"    "1984-02-03"                    date as "%Y-%m-%d"
  "%g"    "84"                            week-based year [00,99]
  "%G"    "1984"                          week-based year
  "%h"    "Feb"                           same as "%b"
  "%H"    "14"                            hour [00-23]
  "%I"    "02"                            hour [01-12]
  "%j"    "034"                           day of the year [001,366]
  "%k"    "14"                            hour [ 0,23]
  "%l"    " 2"                            hour [ 1,12]
  "%m"    "02"                            month number [01,12]
  "%M"    "34"                            minute [00,59]
  "%n"    "\n"                            newline character
  "%p"    "PM"                            a.m. or p.m. equivalent
  "%r"    "02:34:56 PM"                   AM/PM time ("%I:%M:%S %p")
  "%R"    "14:34"                         24-hour time
  "%S"    "56"                            second [00,60]
  "%t"    "\t"                            tab character
  "%T"    "14:34:56"                      time as "%H:%M:%S"
  "%u"    "5"                             Monday-based weekday [1,7]
  "%U"    "05"                            week number [00,53]
  "%V"    "05"                            week numver [01,53]
  "%w"    "5"                             weekday [0,6]
  "%W"    "05"                            week number [00,53]
  "%x"    "02/03/84"                      date ("%m/%d/%y")
  "%X"    "14:34:56"                      time ("%H:%M:%S")
  "%y"    "84"                            two-digit year [00,99]
  "%Y"    "1984"                          year
  "%z"    "+0700"                         offset from UTC
  "%Z"    "MST"                           time zone
  "%%"    "%"                             percent character
  "%Ec"   "Fri Feb  3 14:34:56 1984"      
  "%EC"   "19"                            
  "%Ex"   "02/03/84"                      
  "%EX"   "14:34:56"                      
  "%Ey"   "84"                            
  "%EY"   "1984"                          
  "%Od"   "03"                            
  "%Oe"   " 3"                            
  "%OH"   "14"                            
  "%OI"   "02"                            
  "%Om"   "02"                            
  "%OM"   "34"                            
  "%OS"   "56"                            
  "%Ou"   "5"                             
  "%OU"   "05"                            
  "%OV"   "05"                            
  "%Ow"   "5"                             
  "%OW"   "05"                            
  "%Oy"   "84"