As Lookingforajob, says, many airports do work at night, but as a general rule, if it's not required by CAP168 or the pilot landing then switch it off. Aerodrome Ground Lightning is horrendously expensive to run, both in terms of energy cost, even with LED lamps, cost of renewal of the lamps (based on hours run) cabling and other equipment.
The same goes for Apron lighting, if no-one needs to be working on the standf then that too should be switched off.