Dumaguete airport runway has night lights. A few months ago i've seen them in bright daylight (maebe testing) but i think that a runway needs also some electronic guiding system for night landing plus approval from some international instance (because of international passengers).
Even if they install ILS at the airport, I don't think there would still be night flights. Problem is if there will be night flights, it would most probably be only uni-directional at runway 27... It would be difficult for pilots to land from Runway 09 considering that even during day time, the rising terrain already triggers the terrain warning system and pilots just override them... another thing to consider is that the runway is parallel to the sea, making runway 27 susceptible to crosswinds... I don't think airlines would risk operating flights that may just be cancelled due to runway and terrain limitations.
