Hi Redsquirrel111, I have no idea how to make an event time-related in bitsy, sorry🙁.
But, do you really need it to be time-related?
I like your concept, and I think you can give the same feeling of hurry and stress by making battery loss interaction related. You can hide in every interaction a change in a variable or in an item that will represent the time passing and use the branching list to change interaction based on the battery left. You can also hide “invisible” objects in empty spaces of the monitor to make lose extra time to people who explore the useless area of the phone.
I know is a bit different game from the one you were planning but, this way, you can develop your concept with the standard bitsy features.
Hope you find the best solution and can’t wait to play the game!