The Hour the Schedule Says

Two hours, written separately

The commonest muddle in this trade is a single time on a record that nobody is sure the meaning of. Is it when the car should arrive, or when the traveler has to be somewhere?

So the desk writes both. The ticket hour is a fact and does not move unless somebody else moves it. The wanted hour is what the traveler has in mind, and it is often either generous or optimistic.

Working one from the other

Given the ticket hour, an operator works backwards through the things it knows about: the run itself at that hour of that day, what the far end is like at that time, and how much slack it wants for the day going badly.

That arithmetic belongs to the operator. This desk records the inputs and passes them on, and it does not perform the calculation itself or present a result as though it were checked.

What this desk will not say

It will not say a car will arrive at a particular minute, because it does not dispatch the car. It will not describe any margin as safe. And it will not tell anybody how early to leave for a flight, which is between the traveler and the carrier they bought the ticket from.

What it will do is make sure both hours are on the record so the operator is deciding with the full picture.

When it changes

A moved schedule is passed on the moment the desk hears it. Whether the allocated car still fits the new arithmetic is the operator's answer, and the desk reports it rather than predicting it.