-t<date>   Select files NEWER than or EQUAL to date
  -T<date>   Select files OLDER than date

  This option will allow you to select files according to their date.  The
  date specifier is a six-digit number conforming to the following formats:

  "American" style: mmddyy
  040193     April 1st, 1993
  103189     October 31st, 1989

  "European" style: ddmmyy
  010493     1 April, 1993
  311089     31 October, 1989

  "Japanese" style: yymmdd
  930401     1993 April 01
  891031     1989 October 31

  PKZIP adapts itself to the date format for which your machine is
  configured automatically.

  All users within the United States use the first date format.

  If you are outside the United States and are unsure of the configuration
  of your computer, enter the DATE command at the DOS prompt.  This will
  show you the date format being used on your computer.

  The -t and -T options may be combined to specify a date range.

  These examples all use the "American" date format (mmddyy).  To compress
  all files created after or on November 4, 1992:

     pkzip test.zip -t110492

  To compress all files created before January 10, 1991:

     pkzip test.zip -T011091

  To compress all files created between October 1, 1992 and October 31,
  1992:

     pkzip test.zip -t100192 -T103192

  If -t is used with no date, files with dates equal to the current date are
  specified:

     pkzip today.zip -t