As far as i know there is no display on saturday only sunday, and the only time i know is 4-30 for the red arrows. The times will be in the programmes you can buy, which is okay if you live in Whitehaven but if you don't (like me) tough luck it seems.
I think it was because, when the flying times were published in the jamland news, people didn't need to buy a programme so they stopped giving them out which i don't suppose you can blame them, however a simple message saying the flying would begin mid afternoon, for example, would give people an idea when to get through then they could buy a programme to get the definite times when they arrive. The Red Arrows time is confirmed and as they are usually last i think i might go about 2-30.
Even if you buy a programme the times can be altered or planes don't show up for whatever reason, as has happened in the past, and unless you are in the harbour area and can hear the announcement telling you so (above the noise of the fair) you don't know.