If I have a complex schedule with an hourly interval clock and a cron clock - will there be 2 runs 1 of the clocks take precedence for an overlap, or will there be 2 scheduled runs?

There will be two runs because this is a use case when you can have different parameters associated with the clocks

Can I use an adjustment filter to forgo one of the schedules for the clash time?

I am not sure because the filter is on a schedule level right? Not the clock level?

Yes - you’re right, it is on the schedule level

Can you explain your use case? what would be your end goal by setting this schedule? Can you share the schedule configuration code you have so far?

My end goal is to run 1 more task in a flow for a certain hour of the day - specifically in times of low volume in my system

I think this clock will give you the result you are looking for if you want to have 2 simultaneous flow runs - here is how you can test it:

from datetime import timedelta
from prefect.schedules import Schedule
from prefect.schedules.clocks import IntervalClock, CronClock


schedule = Schedule(
    clocks=[
        CronClock(cron="0 1 * * *", parameter_defaults={"parameter": True}),
        IntervalClock(interval=timedelta(hours=1)),
    ]
)

for sched in schedule.next(20):
    print(sched)

result is that at 1 AM there are 2 runs, as you wanted:

2022-05-06T19:00:00+00:00
2022-05-06T20:00:00+00:00
2022-05-06T21:00:00+00:00
2022-05-06T22:00:00+00:00
2022-05-06T23:00:00+00:00
2022-05-07T00:00:00+00:00
2022-05-07T01:00:00+00:00
2022-05-07T01:00:00+00:00
2022-05-07T02:00:00+00:00
2022-05-07T03:00:00+00:00
2022-05-07T04:00:00+00:00
2022-05-07T05:00:00+00:00
2022-05-07T06:00:00+00:00
2022-05-07T07:00:00+00:00
2022-05-07T08:00:00+00:00
2022-05-07T09:00:00+00:00
2022-05-07T10:00:00+00:00
2022-05-07T11:00:00+00:00
2022-05-07T12:00:00+00:00
2022-05-07T13:00:00+00:00

I’m looking for just 1 run when the clocks clash

but if you want only a specific task to run only in 1 extra run per day, then separating it out into a child flow and scheduling this single run separately (via a different scheduled flow) is the result you are looking for

Got it - thanks Anna and Kevin