My macOS clock is running slow

A rather frustrating issue has cropped up over the last few weeks, and I haven't quite been able to find a solution.
My system clock loses a little bit of ground every single day, and by the end of the week, I’m looking at a discrepancy of nearly ten minutes compared to the actual time.
I have attempted to manually adjust the clock within the date and time settings several times by selecting the Change date and time option, but nothing seems to stick; the clock simply continues to lag behind.
Currently, my time zone is set to GMT -5:00 New York, Boston, Athens, Chicago.
I am running an original version of Windows 7 Home Premium, which has always performed reliably until this point.

P.S.
When I try to input the time manually, the "Apply" button remains greyed out and completely unresponsive once I've finished. I am left with no choice but to click either "OK" or "Cancel."

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.

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?

The only way to actually check if the battery is still good is to pop it out of the motherboard and hit it with a multimeter—you just need to see if it’s still putting out that rated 3V.

And honestly, since you're already in there, you might as well just swap it out. It's a standard CR2032, so you can find one pretty much anywhere, and they aren't exactly expensive ($3.25).

I guess you should be able to handle this yourself without much trouble.
http://en.kioskea.net/faq/625-replac...d-cmos-battery
Just make sure that once you put the battery back in—whether it's the old one or a new one—you head straight into the BIOS to fix the date and time settings.

Many thanks.

you really ought to just turn on that automatic internet clock update setting