Cron Expression
0 0 1 * *
Cron Expression: Cron First Day of Month
Learn how to create a cron expression for 'cron first day of month'. Runs at midnight on the 1st of every month with our free generator tool.
Expression Breakdown
0
Minute(0-59)
0
Hour(0-23)
1
Day(1-31)
*
Month(1-12)
*
Weekday(0-6)
| Field | Value | Meaning |
|---|---|---|
| Minute | 0 | At minute 0 |
| Hour | 0 | At hour 0 |
| Day of Month | 1 | Day 1 |
| Month | * | Any month |
| Day of Week | * | Any day of the week |
This cron expression represents: cron first day of month
Cron Expression
0 0 1 * *
What This Expression Does
Runs at midnight on the 1st day of every month — 12 runs per year. The 1 sits in the day-of-month field; every other field stays open, so the weekday the 1st happens to fall on doesn’t matter.
Use Cases
First-of-the-month jobs usually mark the start of a billing or reporting period:
- Generating invoices and starting new billing cycles
- Resetting monthly usage quotas and rate limits
- Snapshotting month-start balances for accounting
- Partitioning: creating next month’s database table partitions
How to Use
- Copy the cron expression above
- Open your crontab with
crontab -e - Add a new line with:
0 0 1 * * /path/to/your/script.sh - Save and exit
Tip: Month-End Data Isn’t Always Ready at 00:00
If your job summarizes the previous month, midnight on the 1st can race with late-arriving data (payment settlements, timezone stragglers). Running a few hours later — 0 5 1 * * — is a cheap way to dodge most of those races.
Alternative Formats
-
Shortcut syntax:
@monthly /path/to/script.sh— identical to0 0 1 * * -
First of month at 5am:
0 5 1 * * -
1st and 15th (semi-monthly):
0 0 1,15 * *