I'm not 100% sure, but take a look at the section on "Manipulating Other Tasks" https://rocketry.readthedocs.io/en/stable/cookbook/controlling_runtime.html#mani

I'm not 100% sure, but take a look at the section on "Manipulating Other Tasks" https://rocketry.readthedocs.io/en/stable/cookbook/controlling_runtime.html#manipulating-other-tasks https://rocketry.readthedocs.io/en/stable/cookbook/controlli... It seems like what you could do is have a task that runs at some regular interval which would compute the 30 minutes before dawn each day and then add the task with the correct start time directly on the rocketry.args.Session: session.create_task(func=before_dawn_task, start_cond=some_condition)