The number on the clock is by convention, I used to go to work at 2am, I worked nights.
If everyone just published hours in UTC, and availability in UTC, this would work fine. You'd know that normal working hours for your area are you know, 1200-2000 UTC.
- Store all dates and times as UTC when dealing machine interfaces
- Communicate to others as clearly as concisely as possible.
So, I store everything in Postgres as ISO-8601 UTC times, while I tell my friends I'll be there at 8 (even though my watch will say 20:00).
If we adopt hTime, people in some places would go to work at C:00, and in other places at U:00. What’s the difference, really? If you say that people in London think that 8-4 UTC (now 9-5 BST) are working hours and would be confused their NYC colleagues would say they are working 4-12 (now 9-5 EDT), then you get the same “confusion” if London thinks I-Q and NYC says N-V.
We actually can't just use UTC as is and eliminate time zones completely. If we do so, people in some places would go to work at 2am, in other places at 8pm. That's even more confusing. So the clock of hTime aims to use the best of both local and global times worlds in one clock interface.
As for day-changing, I hear you. Again this is UTC, so what the day of UTC is is the day of hTime. Something to work more on indeed.