DateTime::Format::HTTP - Date conversion routines


    use DateTime::Format::HTTP;

    my $class = 'DateTime::Format::HTTP';
    $string = $class->format_datetime($dt); # Format as GMT ASCII time
    $time = $class->parse_datetime($string); # convert ASCII date to machine time


This module provides functions that deal the date formats used by the HTTP protocol (and then some more).


parse_datetime( $str [, $zone] )

The parse_datetime() function converts a string to machine time. It throws an error if the format of $str is unrecognized, or the time is outside the representable range. The time formats recognized are listed below.

The function also takes an optional second argument that specifies the default time zone to use when converting the date. This parameter is ignored if the zone is found in the date string itself. If this parameter is missing, and the date string format does not contain any zone specification, then the floating time zone is used.

The zone should be one that is recognized by DateTime::TimeZone.

Actual parsing is done with the HTTP::Date module. At the time of writing it supports the formats listed next. Consult that module's documentation in case the list has been changed.

 "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-94"         -- old rfc850 HTTP format    (no weekday, no time)
 "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.

If the year is missing, then we assume that the date is the first matching date before current month. If the year is given with only 2 digits, then parse_date() will select the century that makes the year closest to the current date.


The format_datetime() method converts a DateTime to a string. If the function is called without an argument, it will use the current time.

The string returned is in the format preferred for the HTTP protocol. This is a fixed length subset of the format defined by RFC 1123, represented in Universal Time (GMT). An example of a time stamp in this format is:

   Sun, 06 Nov 1994 08:49:37 GMT

format_iso( [$time] )

Same as format_datetime(), but returns a "YYYY-MM-DD hh:mm:ss"-formatted string representing time in the local time zone. It is strongly recommended that you use format_isoz or format_datetime instead (as these provide time zone indication).

format_isoz( [$dt] )

Same as format_iso(), but returns a "YYYY-MM-DD hh:mm:ssZ"-formatted string representing Universal Time.


Gisle Aas (GAAS) for writing HTTP::Date.

Iain, for never quite finishing HTTP::Date::XS.


Support for this module is provided via the email list. See for more details.

Alternatively, log them via the CPAN RT system via the web or email:

This makes it much easier for me to track things and thus means your problem is less likely to be neglected.


Copyright Iain Truskett, 2003. All rights reserved. Sections of the documentation Gisle Aas, 1995-1999. Changes since version 0.35 copyright David Rolsky, 2004.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.000 or, at your option, any later version of Perl 5 you may have available.

The full text of the licences can be found in the Artistic and COPYING files included with this module, or in perlartistic and perlgpl as supplied with Perl 5.8.1 and later.


Originally written by Iain Truskett <>, who died on December 29, 2003.

Maintained by Dave Rolsky <> and Christiaan Kras <>

SEE ALSO mailing list.

perl, DateTime, HTTP::Date, DateTime::TimeZone.