diff --git a/TimeSeries.pm b/TimeSeries.pm
index 39edd64..753ee04 100644
--- a/TimeSeries.pm
+++ b/TimeSeries.pm
@@ -33,7 +33,7 @@ use HTTP::Date qw(parse_date);
 use Time::Local qw(timegm_nocheck);
 use POSIX qw(strftime);
 
-our $VERSION = do { my @r=(q$Revision: 1.17 $=~/\d+/g);sprintf "%d."."%02d"x$#r,@r};
+our $VERSION = do { my @r=(q$Revision: 1.18 $=~/\d+/g);sprintf "%d."."%02d"x$#r,@r};
 
 =head2 new(%opts)
 
@@ -513,10 +513,17 @@ sub get_ticks {
 	$label = '%Y-%m-%d %H:%M';
 
 	$nexttime = sub { return $_[0] + 3600 };
+    } elsif ($lasttime - $firsttime > 1 * 3600) {
+	# 1 to 6 hours: 1 tick per 15 minutes.
+
+	my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime($firsttime);
+	$sec = 0;
+	$min = int($min / 15) * 15;
+	$firsttime = timelocal($sec,$min,$hour,$mday,$mon,$year);
+	$label = '%Y-%m-%d %H:%M';
+	$nexttime = sub { return $_[0] + 15 * 60 };
     } else {
-	# less than 6 hours: 1 tick per minute.
-	# (ok, that's too much - need to find some intermediate steps,
-	# but for now I need graphs over a few minutes.
+	# less than 1 hour: 1 tick per minute.
 
 	my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime($firsttime);
 	$sec = 0;