TikTok's clock is your viewers' clock
A video posted into an empty timezone sits until the audience wakes up, and the first people who do see it may not be the ones you make videos for. Check TikTok analytics for follower activity if the account has any history. If it does not, the evening and lunch windows in the tool are a reasonable first test for a general consumer niche in that audience's local time.
Educational and search-led videos are less fragile about the hour than trend videos. A trend that is already a day old will not be saved by a perfect posting time. Film the durable topic.
Log views only if you also remember the hook
A high view count on a video that started with a stunt, ranked next to a tutorial, will tell you the stunt won the hour. It did not. The tool ranks the numbers you type. Keep the series constant while you test the hour, or the hour gets the credit for the topic.
After four comparable videos, look at the lift versus your median. A daypart at 1.1x is noise. A daypart at 1.5x, twice, is worth moving the calendar toward. Then stop testing hours for a month and test hooks instead.
Put the winners on a calendar
Once a daypart wins, generate four weeks of topics for those weekdays and import the .ics file. Set the event time yourself to the winning hour. The calendar tool deliberately does not invent an hour.