Thanks go to one of the schools for this suggestion!
Someone asked whether it would be possible to show the times of sunrise and sunset on the booking system. That way they could tell at a glance whether the flight was possible (Day / VFR).
This feature is now live, with the times shown just underneath the form. It also shows a moon symbol to the side of the time slots before sunrise and after sunset. Pilots are still expected to check official sunrise and sunset times for their location prior to flight to remain legally within VFR rules.
The system calculates the times for any date chosen. To do this it needs a location (latitude and longitude). You'll find these fields in your system under Admin > Basic settings > Location & time zone.