diff --git a/CHANGED b/CHANGED
index 10ab08b..a171be1 100644
--- a/CHANGED
+++ b/CHANGED
@@ -1 +1 @@
-    [enhancement] - delete unused scheuldes from readings
+    [fix] - delete unused schedules
diff --git a/FHEM/74_GardenaSmartDevice.pm b/FHEM/74_GardenaSmartDevice.pm
index 79db63f..8e15369 100644
--- a/FHEM/74_GardenaSmartDevice.pm
+++ b/FHEM/74_GardenaSmartDevice.pm
@@ -708,7 +708,7 @@ sub WriteReadings {
                     $hash,
                     $decode_json->{abilities}[$abilities]{name} . '-'
                       . $propertie->{name},
-                      (defined ($propertie->{value} ) eq '') ? RigReadingsValue( $hash, 'n/a') : RigReadingsValue( $hash, $propertie->{value} )
+                      (defined ($propertie->{value} ) eq '') ? RigReadingsValue( $hash, 'n/a') : "".RigReadingsValue( $hash, $propertie->{value} ) # cast all data to string with ""
                   )
                   if ( exists( $propertie->{value} ) 
                     && $decode_json->{abilities}[$abilities]{name} . '-'
@@ -735,7 +735,7 @@ sub WriteReadings {
                     $hash,
                     $decode_json->{abilities}[$abilities]{name} . '-'
                       . $propertie->{name},
-                    RigReadingsValue( $hash, $propertie->{value} )
+                    "".RigReadingsValue( $hash, $propertie->{value} )  # cast all data to string with ""
                   )
                   if (
                     defined( $propertie->{value} )
@@ -762,7 +762,7 @@ sub WriteReadings {
                     $decode_json->{abilities}[$abilities]{name} . '-'
                       . $propertie->{name}
                       . '_timestamp',
-                    Time::Piece->strptime(
+                    "".Time::Piece->strptime(
                         RigReadingsValue( $hash, $propertie->{timestamp} ),
                         "%Y-%m-%d %H:%M:%S" )->strftime('%s')
 
diff --git a/controls_GardenaSmartDevice.txt b/controls_GardenaSmartDevice.txt
index 041545f..843e6c1 100644
--- a/controls_GardenaSmartDevice.txt
+++ b/controls_GardenaSmartDevice.txt
@@ -1,2 +1,2 @@
 UPD 2022-07-21_19:43:48 49634 FHEM/73_GardenaSmartBridge.pm
-UPD 2022-08-06_20:17:48 107633 FHEM/74_GardenaSmartDevice.pm
+UPD 2022-08-07_20:12:20 107711 FHEM/74_GardenaSmartDevice.pm