Also, if you are new to Prefect, you may start directly with Prefect 2.0

moving your other messages into the same thread to clean up the Slack thread

I am quite new to Prefect, but my understanding is that the Scheduler service is independent from the agent service. I thought that the scheduler is hosted within Prefect Cloud. Here also the code snippet of my schedule:

today = datetime.date.today()
sunday = today + datetime.timedelta((calendar.SUNDAY - today.weekday()) % 7)
schedule = IntervalSchedule(start_date=sunday, interval=timedelta(weeks=1))

OK, found it. Seems there was an exception at registration time that I missed for whatever reason. The following works now:

today = datetime.date.today()
sunday = today + datetime.timedelta((calendar.SUNDAY - today.weekday()) % 7)
sunday_with_time = datetime.datetime(year=sunday.year, month=sunday.month, day=sunday.day)
schedule = IntervalSchedule(start_date=sunday_with_time, interval=timedelta(weeks=1))

ok, so looks like it's solved for you - LMK if not