Flight Office allows you to easily set up the system with your local twilight hours. Twilight hours are generated using your airport's coordinates, which are entered in Flight Office's administrative area. On the booking sheet, time slot hours (on the left side of the sheet) in red indicates official night time. Where night changes to day (or vice versa), a sunrise/sunset time is given adjacent to the lower time.
In the example below, 05:27 represents official sunrise time for your local airport.