code: def update_payload(self, fields=None):
          
          data = super(SyncPlan, self).update_payload(fields)
          if isinstance(data.get('sync_date'), datetime):
              data['sync_date'] = data['sync_date'].strftime('%Y-%m-%d %H:%M:%S')
          return data
docs: Convert ``sync_date`` to a string if datetime object provided.