HTTP::Date - date conversion routines

SYNOPSIS

        use HTTP::Date;

        $string = time2str($time);    # Format as GMT ASCII time
        $time = str2time($string);    # convert ASCII date to machine time

DESCRIPTION

       This module provides two functions that deal with the HTTP
       date format.  The following functions are provided:

       time2str([$time])
           The time2str() function converts a machine time
           (seconds since epoch) to a string.  If the function is
           called without an argument, it will use the current
           time.

           The string returned is in the format defined by the
           HTTP/1.0 specification.  This is a fixed length subset
           of the format defined by RFC 1123, represented in
           Universal Time (GMT).  An example of this format is:

              Thu, 03 Feb 1994 17:09:00 GMT


       str2time($str [, $zone])
           The str2time() function converts a string to machine
           time.  It returns undef if the format is unrecognized,
           or the year is not between 1970 and 2038.  The
           function is able to parse the following formats:

            "Wed, 09 Feb 1994 22:23:32 GMT"       -- HTTP format
            "Thu Feb  3 17:03:55 GMT 1994"        -- ctime(3) format
            "Thu Feb  3 00:00:00 1994",           -- ANSI C asctime() format
            "Tuesday, 08-Feb-94 14:15:29 GMT"     -- old rfc850 HTTP format
            "Tuesday, 08-Feb-1994 14:15:29 GMT"   -- broken rfc850 HTTP format

            "03/Feb/1994:17:03:55 -0700"   -- common logfile format
            "09 Feb 1994 22:23:32 GMT"     -- HTTP format (no weekday)
            "08-Feb-94 14:15:29 GMT"       -- rfc850 format (no weekday)
            "08-Feb-1994 14:15:29 GMT"     -- broken rfc850 format (no weekday)

            "1994-02-03 14:15:29 -0100"    -- ISO 8601 format
            "1994-02-03 14:15:29"          -- zone is optional
            "1994-02-03"                   -- only date
            "1994-02-03T14:15:29"          -- Use T as separator
            "19940203T141529Z"             -- ISO 8601 compact format
            "19940203"                     -- only date


            "08-Feb-1994"       -- broken rfc850 HTTP format (no weekday, no time)
            "09 Feb 1994"       -- proposed new HTTP format  (no weekday, no time)
            "03/Feb/1994"       -- common logfile format     (no time, no offset)

            "Feb  3  1994"      -- Unix 'ls -l' format
            "Feb  3 17:03"      -- Unix 'ls -l' format

            "11-15-96  03:52PM" -- Windows 'dir' format

           The parser ignores leading and trailing whitespace.
           It also allow the seconds to be missing and the month
           to be numerical in most formats.

           The str2time() function takes an optional second
           argument that specifies the default time zone to use
           when converting the date.  This zone specification
           should be numerical (like "-0800" or "+0100") or
           "GMT".  This parameter is ignored if the zone is
           specified in the date string itself.  It this
           parameter is missing, and the date string format does
           not contain any zone specification then the local time
           zone is assumed.

           If the year is missing, then we assume that the date
           is the first matching date before current time.

BUGS

       Non-numerical time zones (like MET, PST) are all treated
       like GMT.  Do not use them.  HTTP does not use them.

       The str2time() function has been told how to parse far too
       many formats.  This makes the module name misleading. To
       be sure it is really misleading you can also import the
       time2iso() and time2isoz() functions.  They work like
       time2str() but produce ISO-8601 formated strings
       (YYYY-MM-DD hh:mm:ss).

COPYRIGHT

       Copyright 1995-1997, Gisle Aas

       This library is free software; you can redistribute it
       and/or modify it under the same terms as Perl itself.