On Monday, I was able to go for a nice bicycle ride. It was a sunny and warm day with just a little bit of wind. When you are able to get some exercise, you get very inspired.
The little problem that I encountered last weekend with Millie fading to Billy would not occur if UTC Midnight would be the shift change.
With my testing every location and landscape that I could, last weekend I encountered the fading of Millie to Billy due to Tokyo being Monday and USA and Canada still being Sunday. We both agreed that this is a rare occurrence.
What I suggested and it is only a suggestion is to use 00:00 UTC (GMT) on Saturday and on Monday as the change of Millie to Billy (or Billy to Millie). There would not be a chance of fade. But this suggestion has one issue.
If you would use 00:00 UTC (GMT) on Monday (I am using Monday as an example), Monday white Millie would appear at the following locations at the location's time listed.
Monday 09:00 Tokyo, Japan
Monday 04:00 Saint Petersburg, Russia
Monday 01:00 Vienna, Austria
Monday 00:00 UTC (GMT)
Sunday 19:00 Mansfield, Ohio
Sunday 16:00 Roseville, California
These are the times that would display as these are all 00:00 UTC (GMT).
After I set up this chart on my own sheet of paper, it is probably better to leave everything as it is now. But you can think about this for later.