diff --git a/FHEM/90_at.pm b/FHEM/90_at.pm
index 0cfa9f19c..b1e4516a9 100755
--- a/FHEM/90_at.pm
+++ b/FHEM/90_at.pm
@@ -4,6 +4,7 @@ package main;
 
 use strict;
 use warnings;
+use POSIX;
 use Time::HiRes qw(gettimeofday);
 
 #####################################
@@ -35,7 +36,7 @@ at_SecondsTillTomorrow($)  # 86400, if tomorrow is no DST change
   if(!$at_stt{$dayHour}) {
     my @l1 = localtime($t);
     my @l2 = localtime($t+86400);
-    $at_stt{$dayHour} = 86400+($l1[2]-$l2[2])*3600;
+    $at_stt{$dayHour} = 86400+($l1[8]-$l2[8])*3600;
   }
 
   return $at_stt{$dayHour};
@@ -74,14 +75,20 @@ at_Define($$)
 
   my $ot = $data{AT_TRIGGERTIME} ? $data{AT_TRIGGERTIME} : gettimeofday();
   $ot = int($ot) if(!$rel);     # No way to specify subseconds
-  my @lt = localtime($ot);
   my $nt = $ot;
 
-  $nt -= ($lt[2]*3600+$lt[1]*60+$lt[0])         # Midnight for absolute time
-                        if($rel ne "+");
-  $nt += ($hr*3600+$min*60+$sec); # Plus relative time
-  $nt += at_SecondsTillTomorrow($nt) if($ot >= $nt);  # Do it tomorrow...
-  @lt = localtime($nt);
+  if($rel eq "+") {
+    $nt += ($hr*3600+$min*60+$sec); # Relative time
+
+  } else {
+    my @lt = localtime($ot);
+    ($lt[2], $lt[1], $lt[0]) = ($hr+0, $min+0, $sec+0);
+    $nt = mktime(@lt[0..6]);
+    $nt += at_SecondsTillTomorrow($nt) if($ot >= $nt);  # Do it tomorrow...
+
+  }
+
+  my @lt = localtime($nt);
   my $ntm = sprintf("%02d:%02d:%02d", $lt[2], $lt[1], $lt[0]);
   if($rep) {    # Setting the number of repetitions
     $cnt =~ s/[{}]//g;