Online alarm clock for 3:40 am
While preparing early for telescope observations at Tekapo, use the 3:40 am alarm as the point for checking what must be ready before you head outside. That leaves a measured stretch before 4:00 am for fitting an eyepiece, reviewing the target list, and arranging warm layers without turning the preparation into a last-minute scramble.
Because the telescope work begins later, confirm that the alarm will remain able to sound throughout the wait. A browser alarm cannot alert you if its page is closed or the phone or computer falls asleep, which could leave the telescope preparation running late. Keep the page open, prevent sleep, raise the volume to an audible level, and test the sound before relying on 3:40 am.
Once the Tekapo gear is laid out during the night, decide what follows the alarm and leave a small buffer before that next task. Use part of the twenty minutes before 4:00 am to check batteries and note the route to the observing spot, while preserving the final few minutes for an unhurried transition. A dim display can also reduce stray light around the equipment while everything is being readied.