This is not to be misconstrued (as each crew is different), however, a rule of thumb most of us crews go by follows. When the train is late and we are within the time period of 05:30 -- 22:00 (the time period most of us as dining car staff are actually on the clock), the company wants us to make every effort to serve any meal period where that time falls while the train is in operation. There are times when we just can't do that such as something happening ten minutes away from the destination terminal, etc. But anyway, if a train leaves the destination terminal and only half a meal period has past, the diner needs to open and make an abbreviated call for that meal period for the first class passengers, and if possible give the coaches a chance to use the diner with the remaining seating if any after first class are in there. The same is true when the train is close to arriving at the end terminal. If there is sufficient time before the time to clean up and start inventory (which is usually about an hour or hour and a half on Silver Service), the same situation falls into play there, too providing there is sufficient time to feed the passengers and get them moved out of the diner in order to begin clean up and stripping of the car. One thing to remember, is the majority of the dining car crew needs to be finished as other than two crewmembers, our timeclock stops as soon as we hit the bumper at the terminal (unless a manager has adjusted our time sheets and OKed it). And we are usually very tired and wanna get going, anyway!
Generally on train #92 we operate based on the train's location, and we have points we go by in route at each end. Heading into NYP, we are scheduled to arrive at 15:40. We will assume we are operating with an ontime train (HA HA HA HA). In this case we will have either started lunch a few minutes prior to WAS (if the crew opened when they are supposed to) or maybe we needed to wait and open departing WAS (we are supposed to leave there at 11:53-so in theory the HEP is down due to the engine change at 11:30 when we normaly open the car). Our arrival time into WIL is 13:40. The company allows us to close the diner either at WIL (15min or so early) or at 14:00 on time for the end of the meal period. We have to have all passengers OUT of the dining car by the time we arrive in PHL (which is about and hour and a half away from NYP) so we can begin clean up and inventory. We use the same "formula" so to speak when the train is operating behind schedule with a late meal. That late meal is technically supposed to be for the first class passengers, though most of the time (as far as my crew is concerned) we make a call to the coaches on a late meal, too.
Like I said in the beginng of this post, I have went through all this mainly to illustrate the way it supposed to work, but remember each crewbase, train crew, and to put it bluntly each trip (as none are ever the same) is totally different! OBS...