Cron Expression: Cron Last Day of Month

Standard cron has no last-day-of-month syntax. Learn the 28-31 plus date-check idiom, and where Quartz's L expression works instead.

Cron Expression

0 0 28-31 * *

This entry fires on days 28-31; a one-line date check inside the command ensures the job itself only runs on the true last day of the month — see below.

Expression Breakdown

Minute
(0-59)

Hour
(0-23)

28-31

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	`28-31`	Days 28-31
Month	`*`	Any month
Day of Week	`*`	Any day of the week

Here’s an awkward truth: standard Unix cron has no “last day of month” syntax. Months end on the 28th, 29th, 30th, or 31st, and the day-of-month field can’t express “whichever is last.” The standard idiom: fire on all candidate days and let a date check pick the real one.

Cron Expression (the idiom)

0 0 28-31 * *

Combined with a date check in the command:

0 0 28-31 * * [ "$(date -d tomorrow +\%d)" = "01" ] && /path/to/script.sh

How It Works

0 0 28-31 * * fires at midnight on days 28, 29, 30, and 31 — every possible month-end candidate.
date -d tomorrow +%d prints tomorrow’s day number. It equals 01 only when today is the last day of the month, so the && gate runs your script exactly once per month.
The % is escaped as \% because crontab treats a bare % as a newline.

On BSD/macOS, date -d isn’t available — use date -v+1d +%d instead.

Quartz and Friends Support `L` Directly

If you’re scheduling inside a Java app (Quartz), Spring, or another framework with Quartz-style expressions, you get real last-day support:

0 0 0 L * ?

The L in the day-of-month field means “last day.” Some modern cron replacements (and Oracle/Jenkins flavors) accept L too — but classic Linux crontab will reject it, so don’t paste Quartz syntax into crontab -e.

Use Cases

Month-end jobs are the mirror image of first-of-month ones:

Closing out monthly billing before the new cycle starts
Month-end financial reconciliation and ledger snapshots
Final “use it or lose it” quota reminders to customers
Compressing and archiving the month’s logs in one pass

How to Use

Copy the full crontab line (expression + date check) from above
Open your crontab with crontab -e
Paste it, replacing /path/to/script.sh with your job
Save, then sanity-check next month-end in the logs

Alternative Formats

Last day at 11:30pm (before midnight rolls the month): 30 23 28-31 * * [ "$(date -d tomorrow +\%d)" = "01" ] && /path/to/script.sh
Move the check into the script and keep the crontab clean: 0 0 28-31 * * /path/to/month-end.sh with the script exiting early unless tomorrow is the 1st