How are Сhange and Сhange % calculated in the watchlist?
These are the change and change % from the previous daily bar. The data in the watchlist is set to 1D interval by default, therefore the change and change % values are also calculated on 1D interval.
If you are looking at crypto coins that are traded on different exchanges, you need to bear in mind that the exchanges might be running on different timezones too (UTC, UTC+8, etc). You may view the exchange's timetable in the symbol info of each specific instrument.