(\d+)                 # year
	 (?:
	       (?:\s+|:)       # separator before clock
	    (\d\d?):(\d\d)     # hour:min
	    (?::(\d\d))?       # optional seconds
	 )?                    # optional clock
	    \s*
	 ([-+]?\d{2,4}|(?![APap][Mm]\b)[A-Za-z]+)? # timezone
	    \s*
	 (?:\(\w+\))?	       # ASCII representation of timezone in parens.
	    \s*$
	/x)

    ||

    # Try the ctime and asctime format
    (($mon, $day, $hr, $min, $sec, $tz, $yr) =
	/^
	 (\w{1,3})             # month
	    \s+
	 (\d\d?)               # day
	    \s+
	 (\d\d?):(\d\d)        # hour:min
	 (?::(\d\d))?          # optional seconds
	    \s+
	 (?:([A-Za-z]+)\s+)?   # optional timezone
	 (\d+)                 # year
	    \s*$               # allow trailing whitespace
	/x)

    ||

    # Then the Unix 'ls -l' date format
    (($mon, $day, $yr, $hr, $min, $sec) =
	/^
	 (\w{3})               # month
	    \s+
	 (\d\d?)               # day
	    \s+
	 (?:
	    (\d\d\d\d) |       # year
	    (\d{1,2}):(\d{2})  # hour:min
            (?::(\d\d))?       # optional seconds
	 )
	 \s*$
       /x)

    ||

    # ISO 8601 format '1996-02-29 12:00:00 -0100' and variants
    (($yr, $mon, $day, $hr, $min, $sec, $tz) =
	/^
	  (\d{4})              # year
	     [-\/]?
	  (\d\d?)              # numerical month
	     [-\/]?
	  (\d\d?)              # day
	 (?:
	       (?:\s+|[-:Tt])  # separator before clock
	    (\d\d?):?(\d\d)    # hour:min
	    (?::?(\d\d(?:\.\d*)?))?  # optional seconds (and fractional)
	 )?                    # optional clock
	    \s*
	 ([-+]?\d\d?:?(:?\d\d)?
	  |Z|z)?               # timezone  (Z is "zero meridian", i.e. GMT)
	    \s*$
	/x)

    ||

    # Windows 'dir' 11-12-96  03:52PM
    (($mon, $day, $yr, $hr, $min, $ampm) =
        /^
          (\d{2})                # numerical month
             -
          (\d{2})                # day
             -
          (\d{2})                # year
             \s+
          (\d\d?):(\d\d)([APap][Mm])  # hour:min AM or PM
             \s*$
        /x)

    ||
    return;  # unrecognized format

    # Translate month name to number
    $mon = $MoY{$mon} ||
           $MoY{"\u\L$mon"} ||
	   ($mon =~ /^\d\d?$/ && $mon >= 1 && $mon <= 12 && int($mon)) ||
           return;

    # If the year is missing, we assume first date before the current,
    # because of the formats we support such dates are mostly present
    # on "ls -l" listings.
    unless (defined $yr) {
	my $cur_mon;
	($cur_mon, $yr) = (localtime)[4, 5];
	$yr += 1900;
	$cur_mon++;