On the server, ActiveReservationsService keeps track of expiry (based on reservation time) of active reservations. As the client will be shown a timer (for the expiration time), which could be a little out of sync with the server, we can add a buffer of five seconds on the server to safeguard from a broken experience, such that the client never times out after the server, preventing a successful purchase.
does this mean that the server will tell the client that the expiration has expired earlier that it really should? this is to make sure that the client doesn’t get a booking failure when it thinks that it still has time. how does the client get out of sync with the server?