Make buttons hide again when performed_at is not null

app/routes/events-team.tsx

@@ -271,7 +271,7 @@ export default function () {
 
     // Technically this won't be the same as the time in the db, but that doesn't matter since this is just to hide the button
     newEventData[eventData.findIndex((e) => e.id === eventId)].performed_at =
-      Date.now();
+      new Date().toISOString();
 
     setEventData([...newEventData]);
     setSelectedEvent("");
@@ -313,7 +313,8 @@ export default function () {
 
     const newEventData = eventData;
 
-    newEventData[eventData.findIndex((e) => e.id === eventId)].performed_at = 0;
+    newEventData[eventData.findIndex((e) => e.id === eventId)].performed_at =
+      new Date(0).toISOString();
     setEventData([...newEventData]);
     setSelectedEvent("");
     setDisableClicks(false);
@@ -664,9 +665,7 @@ export default function () {
                         </Button>
                       </>
                     ) : null}
-                    {can_approve &&
-                    !event.pending &&
-                    typeof event.performed_at !== "number" ? (
+                    {can_approve && !event.pending && !event.performed_at ? (
                       <>
                         <Button
                           colorScheme="blue"