diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 9dccfb0..46186ab 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -2913,8 +2913,10 @@
 	$date{'iso-8601'}  = sprintf "%04d-%02d-%02dT%02d:%02d:%02dZ",
 	                     1900+$year, 1+$mon, $mday, $hour ,$min, $sec;
 
-	$tz =~ m/^([+\-][0-9][0-9])([0-9][0-9])$/;
-	my $local = $epoch + ((int $1 + ($2/60)) * 3600);
+	my ($tz_sign, $tz_hour, $tz_min) =
+		($tz =~ m/^([-+])(\d\d)(\d\d)$/);
+	$tz_sign = ($tz_sign eq '-' ? -1 : +1);
+	my $local = $epoch + $tz_sign*((($tz_hour*60) + $tz_min)*60);
 	($sec, $min, $hour, $mday, $mon, $year, $wday, $yday) = gmtime($local);
 	$date{'hour_local'} = $hour;
 	$date{'minute_local'} = $min;