I was involved in a fieldtrip, it was just a day trip, where we took first years out to the countryside.
We had just completed the trip and were about to go when a Muslim student came up to the field leader, pointed out the time, and said “I need to go and pray”. Unfortunately, we had to say to the student they couldn’t do that because we needed to go as everyone else on the trip would have been late back off the trip. If we had known before the fieldtrip, we could have been aware of it and figured something out. As a result of this we now have a question on the form asking about religious requirements on trips to avoid this situation happening again.