I thought I found a fix. This was disabled by default. It seemed to briefly solve it in my desktop view.
But not in my phone view. It’s also not showing the timezone lable. Arrgh!
I’ve reached out to Sites Community for support. We’ll see. It appears to be a common issue. For whatever reason embedding the code for a calendar works correctly, but the Sites gadget for Calendars doesn’t seem to adjust for daylight vs regular times. Odd little issue. Time sucker.