Are you sure? My F91W doesn't even ask for year in settings. How would have it known it is a leap year or not.
Some other models (not F91W) does track year.
I was responding to the claim about the Samsung Watch not showing the right date, I unfortunately have never owned the older kinds of "smartwatches" :)
Are they using a third party watch face?
My Galaxy Watch 4 has no issues.
I have a custom watch face on my GW4 and it's showing the 29th