@node HTTP/Date, HTTP/Headers, HTTP/Daemon, Module List
@unnumbered date conversion routines


@unnumberedsec NAME

time2str, str2time - date conversion routines

@unnumberedsec SYNOPSIS

@example
use HTTP::Date;
@end example

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

@unnumberedsec DESCRIPTION

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

@unnumberedsubsec 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:

@example
Thu, 03 Feb 1994 17:09:00 GMT
@end example

@unnumberedsubsec 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:

@example
"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
@end example

@example
"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)
@end example

@example
"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
@end example

@example
"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)
@end example

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

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 @emph{before} current time.

@unnumberedsec 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 :-)

