7 game days for me. Got killed, spawned naked in a nearby base and the drakes stayed 7 days around, and were like following me. My other teleport bases are on another islands. I made some gears and a raft, went to to closest teleport across the sea and teleport into the attacked base. As soon i was inside the event ended. 7 days waiting and the solution was only to get inside the base to make it end...