Update README.md

Author: Nijamudeen-Mohamed

README.md

@@ -39,11 +39,9 @@ body: Column(
 ), 
 
 void _viewChanged(ViewChangedDetails viewChangedDetails) { 
-  SchedulerBinding.instance.addPostFrameCallback((duration) { 
-    setState(() { 
+  SchedulerBinding.instance.addPostFrameCallback((duration) {  
       _datePicked = viewChangedDetails 
-          .visibleDates[viewChangedDetails.visibleDates.length ~/ 2]; 
-    }); 
+          .visibleDates[viewChangedDetails.visibleDates.length ~/ 2];  
   }); 
 } 
 ```