diff --git a/fhem/webfrontend/pgm3/CHANGED b/fhem/webfrontend/pgm3/CHANGED
index 084e4072f..afad4d263 100644
--- a/fhem/webfrontend/pgm3/CHANGED
+++ b/fhem/webfrontend/pgm3/CHANGED
@@ -141,4 +141,4 @@ It is not necessary to tell fhem that there are other logs.
 -- feature: optimized speed for small devices (more than 50 percent on e.g a NSLU2)
 
 2007-10-24 (071024cvs)
--- bugfix: at least one new picture per day for userdefs (gnuplot picture)
+-- bugfix: at least one new picture per hour for userdefs (gnuplot picture)
diff --git a/fhem/webfrontend/pgm3/HISTORY b/fhem/webfrontend/pgm3/HISTORY
index 7ccbde216..49d1e9caf 100644
--- a/fhem/webfrontend/pgm3/HISTORY
+++ b/fhem/webfrontend/pgm3/HISTORY
@@ -41,4 +41,4 @@
  - every module now checks if a redraw of the picture is really necessary. If not the old picture will be sent. The time to reload the screen now is down to less than 50 percent.
 
 - Martin 2007-10-24
- - Change in userdefs.php. At least one new picture per day for userdefs (gnuplot picture)
+ - Change in userdefs.php. At least one new picture per hour for userdefs (gnuplot picture)
diff --git a/fhem/webfrontend/pgm3/include/userdefs.php b/fhem/webfrontend/pgm3/include/userdefs.php
index c3d79472d..24d3af1db 100755
--- a/fhem/webfrontend/pgm3/include/userdefs.php
+++ b/fhem/webfrontend/pgm3/include/userdefs.php
@@ -40,9 +40,9 @@ include "functions.php";
  	$parts = explode(" ", $tail1[0]);
 
 
-	$today= date("d");
+	$today= date("H");
         $savefile=$AbsolutPath."/tmp/USERDEF.".$drawuserdef.".log.".$parts[0].".png";
-	$fmtime=date ("d", filemtime($savefile)); #at least one new graphic per day (gnuplot)
+	$fmtime=date ("H", filemtime($savefile)); #at least one new graphic per hour (gnuplot)
 	if ((file_exists($savefile)) and ($fmtime == $today)) {
 
 		$im2 = @ImageCreateFromPNG($savefile);