I'm using Time Range Switch to turn on my irrigation at dawn. I want it to switch off 30 minutes later. Because dawn only occurs once/day, it's difficult to run a debug.
I tried it this morning and it came on as scheduled. However, I think it turned off again 10 minutes later.
It helps if you share exactly what Node package you are using. There are quite a few that deal with dates/times and schedules.
I was using CRON+ for this kind of thing. But recently I've started using node-red-contrib-sun-position as I needed some different outputs that were easier than with CRON+. It's "enhanced inject" node would do what you want.