There's no need for it to sync with the server so often. Any device connected to the internet is likely to be synced already and as such just grabbing the system time at start up and using that as a base is fine. I think syncing with the server would be a bit overkill as well. But yeah if the calculation isn't working properly then that is a problem. Maybe a sync every hour just for the rare cases it is wrong or screwed up is enough?