Countdown Timer - Harlowe

Hello,

Apologies if this is posted elsewhere, but I keep seeing countdown timers for Sugarcube, and not Harlowe. I'm looking for a simple countdown timer that will display live (starting at 30s), and at 0s automatically forward to a different passage. The timer does not need to be global, as it's limited to one specific passage/stage of the game.

Any help is greatly appreciated! (also, I'm using Twine 2.0.1, Harlowe format)