That was already fixed

app/src/Dialog.svelte

@@ -41,7 +41,7 @@
 		tempDate.setHours( taskData.time.match( /(\d{2}):\d{2}/ )[1] );
 		tempDate.setMinutes( taskData.time.match( /\d{2}:(\d{2})/ )[1] );
 
-		if (tempDate.getTime() / 1000 < Date.now()) {
+		if (tempDate.getTime() < Date.now()) {
 			dateError = "date_past";
 			return;
 		}