Day-Night Cycle Longer Than 20 Minutes on Realm

We're developing an app that keeps track of the time and date of our Minecraft Windows 10 realm for fun with our own time and date system, since the day-night cycle continues regardless of anyone being on it, but the sky lags every few seconds and has to redo its movement in the past few seconds, so the day-night cycle can range anywhere from 20 minutes and 50 seconds to 22 minutes and 30 seconds, never a round 20 minutes like it should be. This makes it impossible to be able to keep track of days. There's too much variance. It'd be nice if there was some check that made sure every day-night cycle was 20 minutes exactly.