diff --git a/FHEM/74_GardenaSmartDevice.pm b/FHEM/74_GardenaSmartDevice.pm
index d2bf554..db63b3a 100644
--- a/FHEM/74_GardenaSmartDevice.pm
+++ b/FHEM/74_GardenaSmartDevice.pm
@@ -407,7 +407,7 @@ sub Set {
     }
     elsif ( lc $cmd eq 'on' || lc $cmd eq 'off' || lc $cmd eq 'on-for-timer' ) {
         my $val = (
-            defined($aArg) && ref($aArg) eq 'ARRAY'
+            scalar(!@$aArg == 0) && ref($aArg) eq 'ARRAY'
             ? $aArg->[0] * 60
             : lc $cmd
         );
diff --git a/controls_GardenaSmartDevice.txt b/controls_GardenaSmartDevice.txt
index 3ab01be..4507d86 100644
--- a/controls_GardenaSmartDevice.txt
+++ b/controls_GardenaSmartDevice.txt
@@ -1,2 +1,2 @@
 UPD 2021-06-28_15:56:58 47009 FHEM/73_GardenaSmartBridge.pm
-UPD 2021-07-12_11:56:06 56210 FHEM/74_GardenaSmartDevice.pm
+UPD 2021-07-13_17:21:48 56216 FHEM/74_GardenaSmartDevice.pm