Run Once Monthly on the First Day at 3 PM | CronBase
0 15 9 l * ? Once a month on the first day at 3 PM
* In a Nutshell
The cron expression 0 15 9 l * ? runs Once a month on the first day at 3 PM. This cadence is crucial for processes that must execute only once per month, such as generating end-of-month financial reports, processing monthly subscriptions, or performing system-wide maintenance that should not occur more frequently. Running it on the first day ensures timely completion before other dependent tasks begin.
* When to use this
Use 0 15 9 l * ? when a recurring task needs to run Once a month on the first day at 3 PM. It uses Quartz Scheduler (6–7 Fields) syntax, supported by Unix cron daemons, cloud schedulers such as AWS EventBridge, and container orchestration platforms such as Kubernetes CronJob.
CronBase parses 0 15 9 l * ? using a dialect-aware rules engine that identifies the Quartz Scheduler (6–7 Fields) format, validates field structure against the Quartz Scheduler (6–7 Fields) specification, and produces the translation above. Next run times are calculated by forward-scanning from the current UTC clock. Learn how CronBase works.
Frequently Asked Questions
What does the `0 15 9 l * ?` cron expression specifically do?
This cron expression is configured to run a task exactly once per month, specifically on the first day of the month at 3:00 PM. It will not trigger on any other day or at any other time.
How does this schedule handle time zones and daylight saving time changes?
Cron expressions are evaluated based on the server's or system's configured time zone. Daylight Saving Time shifts may cause the job to run an hour earlier or later on the affected days, depending on the direction of the shift.
How can I verify that my task is running at the scheduled time?
You can verify the execution by checking your application's logs for entries related to the task, confirming that it started and completed around 3 PM on the first day of the month. Monitoring tools can also provide confirmation.
What is a potential gotcha with running tasks only once a month?
A common pitfall is forgetting to adjust the schedule for leap years or if the task depends on data that is only available after a certain point in the month. Ensure all dependencies are met before the first day.
What is a common variation of this monthly schedule?
A common variation is to run the task on the last day of the month instead of the first. This is useful for processes that need to finalize data from the entire preceding month.
Related Concepts
* Try any expression
Standard, Quartz, AWS EventBridge, Jenkins, named schedules (@daily, @hourly…)