In Lost, how often must the numbers be entered into the Swan station computer?

In Lost, the numbers must be entered into the Swan station computer every 108 minutes.

The Swan station’s computer displays a countdown, and its occupants are instructed to enter the sequence 4, 8, 15, 16, 23, 42 before the timer reaches zero. Desmond Hume has been performing this task for years when Jack, Locke, and the other survivors discover the station. The routine initially appears to be a psychological experiment, but the show connects it to the island’s electromagnetic properties and the DHARMA Initiative’s research.

The 108-minute interval is also the sum of the six famous numbers: 4 + 8 + 15 + 16 + 23 + 42 equals 108. The countdown and the number sequence are related but not identical facts, so answers naming only “the numbers” do not answer the timing question. The Swan storyline is chiefly explored during the second season.