On studio.twitter.com, when you schedule a broadcast for example from 1am to 2am but you decide to stop before the end so you simply stop streaming from OBS, the broadcast will get the status “timed out”. Instead, if you live until the end of the schedule, it will have the status “ended”.

It is impossible using studio.twitter.com to update the Custom start time in the Replay settings after the end of the schedule (i.e. at 01:30am you could stop streaming and then at 01:35am set the start time, but at 02:01am you won’t be able to do it anymore) without getting this error :
Invalid update: Your change could not be saved because scheduled end time must be in the future.

In my browser terminal I can see it does this requests :
POST https://studio.twitter.com/2/live/broadcast/update.json?owner_id=my_id&user_id=my_id 400 (Bad Request)

There must be a way to hack around this limitation but I couldn’t find one yet. I’m sure I’m not the first one encountering this issue but so far I had no success in finding a solution.