Creating a schedule

Now that you know what makes up a schedule, let’s create one. To do this, we’ll use the ScheduleDefinition class.

We can use dg again to scaffold our schedules. So first run:

dg scaffold dagster.schedule schedules.py

This will create a file in defs/schedules.py where we can add the following schedule code:

import dagster as dg
from dagster_essentials.defs.jobs import trip_update_job

trip_update_schedule = dg.ScheduleDefinition(
    job=trip_update_job,
    cron_schedule="0 0 5 * *", # every 5th of the month at midnight
)

Let’s look at what this code does:

1. Imports the ScheduleDefinition class
2. From the jobs module, import the trip_update_job job
3. Used ScheduleDefinition to create a schedule that:
   • Is attached to the trip_update_job job
   • Has a cron expression of 0 0 5 * *

Checking our schedule

To ensure the schedule is working as expected we can run a quick dg check defs to make sure everything loads correctly. Next we can rerun dg list to see that schedules are now included as part of the output.

> dg list defs
...
Schedules
┏━━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━┓
┃ Name                     ┃ Cron schedule ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━┩
│ trip_update_job_schedule │ 0 0 5 * *     │
└──────────────────────────┴───────────────┘