Author image Ralf S. Engelschall


time2str, str2time - date conversion routines


 use HTTP::Date;

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


This module provides two functions that deal with the HTTP date format.


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-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.

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.


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 1995-1997, Gisle Aas

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