Homepod mini timezone
I saw this question a while ago (2021) and it is still not fixed. When the homepod is on a network on a timezone border, it picks what it thinks is the correct time. It does not sync with the phone or router.
I have my router and phone hard set to Eastern time, but the homepod insists on staying in central time regardless. So you can never ask Siri what time it is cuz she's an hour off.
Apple please fix this. Just add a setting in the homepod for the timezone you want it to be in.