Decrease progress bar using a count based on time intervals

Users have a “energy level” progress bar. I want the progress bar to decrease in 30min intervals by 25%.

a)Ideally this could be automated by pressing clicking an admin level button to start the process.

b)If I have to do it manually, then a button using increments.

Not sure if a) is even possible and I should focus on the manual b).

Any ideas about how to accomplish either a) or b)

For b) I came up with this simple sequence: column A1(energy obtained when user toggles switch to “consume meal”). B1(increments activated by button). C1(B1/4-decreases energy bar 25pts). D1(C1*100). E1(A1-D1). I am going to display a timer app on the wall inside the spaceship and at 30min. intervals I will press the “hunger button”…that all my beginner skills could come up with for now. The a) version is beyond me at this time to figure out-- but if you have an idea on how to make it so, let me know.

Using all Glide columns, this one depletes 7% every 5 minutes. Didn’t do the math right, obviously—made it in under a minute. But it’s possible:
Screen Shot 2020-10-12 at 2.06.54 PM

Do tell maestro…my case use is that the bar level gets resupplied when the student “eats a meal” (a roll up in sum in the user profile). Can you share details of how you pulled that off? Would it fit with my case use?