Motherboard losing min or two a day on system clock

[NeoPTLD]

I leave this computer turned on 24/7 and have Windows resynch every week (interval can't be changed), but I noticed between syncs, the computer's clock comes 1 to 2 minutes behind every day.

What's causing this? It didn't used to go off this much.

 

[SerpentRoyal]

Replace the CMOS battery. Could be a defective on-board clock oscillator.