Apple Watch Displays the Wrong Time

So, the Watch is connected to cellular when this occurs? On the Apple Watch itself, press the Digital Crown, then go to the Settings app. From there, go to Clock. Is that display time ahead at 0?

Try resetting the Watch. Hold the Digital Crown and power button together until you see the Apple logo and then release. The Watch will reboot. See if that changes it.

It actually might not be the digital clock that you are seeing and instead something quirkly like sunrise/sunset. Took me a minute to realize that. Try setting the section to a custom time/location by adding your city into the world clock and then having that be on the clocks home screen

I have exactly the same problem - the time is one hour ahead whenever my cellular Apple Watch is not connected to my iPhone, and fixes itself as soon as it reconnects to my iPhone.

I just updated to watchOS 6.2.5 this morning and the issue persists. Resetting the watch doesn’t help, and neither does unpairing and re-pairing the watch.

I'm not aware of any other setting for the two devices that would affect the time. The Watch gets is time from the paired iPhone location settings. Have you changed any date/time settings on the iPhone. Do you have the settings in the Watch app on the iPhone like Language and Region different than Mirror my iPhone?

Try turning wifi off on your watch, then Bluetooth off on your iPhone.

Then turn Bluetooth back on

and and wifi back on on the watch

Is the Watch one with cellular capabilities and is it activated with cellular?

You have the option to contact Apple support for assistance. You can speak with them over the phone or chat. https://getsupport.apple.com/