monthly_partitioned_config is broken because of wrong cron scheduling

Summary

I’m a bit surprised this hasn’t been reported before, so maybe it’s on me.

Basically, when using a monthly_partitioned_config and running with any key, I get the following error:

croniter.croniter.CroniterBadCronError: [0 0 0 * *] is not acceptable, out of range

inspecting the source code the reason is the method get_cron_schedule has 1 as a default value for the argument day_of_week. This method receives a monthly ScheduleType as only argument when running a monthly partitioned job. Therefore the output cron schedule is “0 0 0 * *”, which isn’t valid for the croniter library that dagster uses.

The fix to this would be as simple as changing the default value of that argument to 1. I can open a PR if you’re fine with it.

Reproduction

from dagster import job, monthly_partitioned_config
from datetime import datetime


@monthly_partitioned_config(start_date=datetime(2021, 1, 1))
def config(start: datetime, _end: datetime):
    pass


@job(config=config)
def some_job():
    pass

if __name__ == "__main__":
    previous_month = "2021-03-01"
    some_job.execute_in_process(partition_key=previous_month)

Additional Info about Your Environment

dagster==0.13.14

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Message from the maintainers:

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[gibsondan]

This was fixed in 0.13.15, yeah. Either upgrading dagster or downgrading croniter on that version will fix this.

[Tiri1992]

I’m using version 0.13.8 and just ran into the same issue. Did we get a fix for this? I’ll downgrade croniter in the meantime.