"A sudden change especially during this period could cause severe disruptions to travel plans resulting in loss of onward connections on other airlines which are also experiencing heavy loads at this time."
Sri Lankan stopped its 24 hour schedule after the government closed the Katunayake international airport during the night, following raids by Tamil Tiger guerilla aircraft to a nearby military base.
The government opened the airport this month, saying it had beefed up defenses against Tiger aircraft incursions.
The airline says it has started to talk to its insurers about night flights.
A Tiger attack on the airport in the past sent insurance premium