George Sanders37 said:How old is the computer?
It probably needs a new CMOS battery on the motherboard—the one used to keep the date and time settings accurate.
The machine is seven years old, and the only hardware issue I've encountered was with the graphics card, which I replaced back in 2010.
I am quite diligent about maintenance and keeping everything clean. On an annual basis, I perform one or two macOS reinstalls, and I have never run into this specific issue before.
The last time I did a full OS reinstall was in November of last year.
Is there any practical way for me to test the health of the battery using basic tools at home?