21 hours ago, pointertovoid said:

did other people observe an abnormal clock reset on their mobo?

I had the problem recently. I replaced the battery and problem's gone

17 hours ago, Mcinwwl said:

I had the problem recently. I replaced the battery and problem's gone

You mean like it happens normally to 99.99999% of people with a PC having an exhausted battery when they change it with a new one?

The issue pointertovoid raised is about two different PC's, where the battery was replaced with a new one BUT that lost date in a week or however when only a small amount of time passed since the replacement. 

It could be also some sort of planned obsolescence taken to the extreme or a bad batch of new batteries, but I don't think they both came from the same source and probably the two batteries are not even the same brand.

jaclaz

5 hours ago, jaclaz said:

It could be also some sort of planned obsolescence

On some cellphones you can set up a current date only within some absurd time frame (like 2005-2015, and rest i blocked), so this is actually interested hypothesis to investigate. Which would require checking people with the same MoBo/BIOS for the same issue.

5 hours ago, jaclaz said:

bad batch of new batteries, but I don't think they both came from the same source and probably the two batteries are not even the same brand.

If they came from the same store, it can be a case of bad storage (exposition to heat/cold or sunlight for a long time) or unfair seller dealing some production dropouts. This requires verifying your assumption to be confirmed or rejected.

12 hours ago, Mcinwwl said:

... within some absurd time frame (like 2005-2015, and rest i blocked), ...

Only for the record, once (when we were poor) calendars were stored and re-used

Years repeat themselves, see:

https://www.whencanireusethiscalendar.com/

https://www.whencanireusethiscalendar.com/moreinfo/

and:

https://garyc.me/calendars/

So, you can set 2013 for 2019 (but 2020 wll be tricky )

jaclaz

Well, ok if you use cellphone's calendar only to match day-month with day-of-week, worse when you need timestamps device adds to notes/messages/photos etc. created, or other activities that cannot be easily emulated in analogue reality.