Fly into and out of Colombo International Airport (Bandaranaike International Airport)
An arrival transfer will be waiting for you irrespective of the time you arrive on day one, but if possible aim to arrive by early afternoon so you have the chance to settle in a freshen up before meeting the group at around 5pm.
When booking your flight home, do remember that Colombo airport is around 2.5 hours away, so a morning flight would mean a very early start.
Please note that there are two departure transfers. One leaves at 7am back to the airport, which is suitable for flights from 12pm. The other leaves at 11am, which takes everyone back to Jetwing Lagoon, where you would have likely spent your first night of the trip.
Here, you can purchase a day pass for roughly $15 which will allow you to relax by the pool. The hotel can then arrange a taxi for you to the airport in time for your flight.