I use timers all the time in my apps. And they update every minute. Use Google scripts for a timer, its easy and takes very little resources. One of my apps runs a 30 minute timer and when it ends rotates people to the bottom of the list, even allows them to pull themselves out early and the timer automatically restarts on its own as well. The timer even knows what time of day it is so if it is past time it wont start a timer til the following day. Hell, the timer even sends text notifications to people being sent to bottom of list after time is up as well as 1st, 2nd, and 3rd positions that got rotated into their new positions.