$yr-- if $mon > $cur_mon;
    }
    elsif (length($yr) < 3) {
	# Find "obvious" year
	my $cur_yr = (localtime)[5] + 1900;
	my $m = $cur_yr % 100;
	my $tmp = $yr;
	$yr += $cur_yr - $m;
	$m -= $tmp;
	$yr += ($m > 0) ? 100 : -100
	    if abs($m) > 50;
    }

    # Make sure clock elements are defined
    $hr  = 0 unless defined($hr);
    $min = 0 unless defined($min);
    $sec = 0 unless defined($sec);

    # Compensate for AM/PM
    if ($ampm) {
	$ampm = uc $ampm;
	$hr = 0 if $hr == 12 && $ampm eq 'AM';
	$hr += 12 if $ampm eq 'PM' && $hr != 12;
    }

    return($yr, $mon, $day, $hr, $min, $sec, $tz)
	if wantarray;

    if (defined $tz) {
	$tz = "Z" if $tz =~ /^(GMT|UTC?|[-+]?0+)$/;
    }
    else {
	$tz = "";
    }
    return sprintf("%04d-%02d-%02d %02d:%02d:%02d%s",
		   $yr, $mon, $day, $hr, $min, $sec, $tz);
}


sub time2iso (;$)
{
    my $time = shift;
    $time = time unless defined $time;
    my($sec,$min,$hour,$mday,$mon,$year) = localtime($time);
    sprintf("%04d-%02d-%02d %02d:%02d:%02d",
	    $year+1900, $mon+1, $mday, $hour, $min, $sec);
}


sub time2isoz (;$)
{
    my $time = shift;
    $time = time unless defined $time;
    my($sec,$min,$hour,$mday,$mon,$year) = gmtime($time);
    sprintf("%04d-%02d-%02d %02d:%02d:%02dZ",
            $year+1900, $mon+1, $mday, $hour, $min, $sec);
}

1;


__END__

=head1 NAME

HTTP::Date - date conversion routines

=head1 SYNOPSIS

 use HTTP::Date;

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

=head1 DESCRIPTION

This module provides functions that deal the date formats used by the
HTTP protocol (and then some more).  Only the first two functions,
time2str() and str2time(), are exported by default.

=over 4

=item 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 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

=item str2time( $str [, $zone] )

The str2time() function converts a string to machine time.  It returns
C<undef> if the format of $str is unrecognized, otherwise whatever the
C<Time::Local> functions can make out of the parsed time.  Dates