Cron Twice a Week

0 7 * * 2,4

At 07:00 on Tuesday and Thursday

Field by Field

Field	Value	Matches
Minute	0	0
Hour	7	7
Day of month	*	every day
Month	*	every month
Day of week	2,4	2, 4

Lists in the Day-of-Week Field

2,4 matches Tuesday and Thursday. Lists, ranges and steps can be mixed freely in the same field: 1-3,5 is Monday through Wednesday plus Friday.

Named days work too — TUE,THU — and are far harder to misread than numbers when someone reviews the crontab a year later.

Why Tuesday and Thursday

Midweek days avoid both the Monday backlog and the Friday deploy freeze. For anything that generates work for a human — a review reminder, a data-quality report, a dependency-update PR — landing on Tuesday and Thursday means there is always a working day left to act on it.

Spacing Is Uneven

Tuesday to Thursday is two days; Thursday to Tuesday is five. If the job processes a backlog, the Tuesday run handles more than twice what the Thursday one does. Size timeouts and batch limits against the larger gap, not the average.

1,4 (Monday and Thursday) splits the week more evenly at 3 and 4 days if that matters.

Time Zones

Standard crontab evaluates in system local time. Vercel Cron, GitHub Actions, Kubernetes CronJobs and AWS EventBridge all evaluate in UTC. If converting your local time crosses midnight, the day-of-week field shifts too — weekdays at 5pm in UTC-07:00 is 0 0 * * 2-6, not 0 0 * * 1-5.

The Day-Field Trap

When both the day-of-month and day-of-week fields are restricted, cron matches either, not both. 0 0 13 * 5 runs on every 13th *and* every Friday — not Friday the 13th. Leave one of them as * unless you genuinely want the union.

Other Common Schedules

Expression	Runs
* * * * *	Every minute
*/5 * * * *	Every 5 minutes
*/15 * * * *	Every 15 minutes
0 * * * *	Every hour, on the hour
0 0 * * *	Every day at midnight
0 9 * * *	Every day at 9am
0 9 * * 1-5	Weekdays at 9am
0 9 * * 1	Every Monday at 9am

Making the Job Safe

• Assume double firing. DST transitions, restarts and retries all cause it. Make the job

idempotent rather than assuming exactly-once.

• Assume overlap. Cron starts the next run whether or not the last one finished. Take a

lock.

• Avoid :00. Every hourly job on the internet fires at the top of the hour; a random

minute spreads load on shared APIs.

• Log the start and end. A cron job that silently stops running is invisible until

someone notices the missing output.