★ Cron cheat sheet
Cron Expression: Every Day at Midnight
The classic nightly job, the same as @daily and @midnight. Midnight in which zone is the question to answer first.
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The expression
0 0 * * *
At 00:00.
- 0Minute
- 0Hour
- *Day of month
- *Month
- *Day of week
✓ Valid 5-field cron
Quick picks
Typing by hand. Pick a pattern above to build one with inputs instead.
In plain English
At 00:00.
Next 10 runs
Paste it into your platform
Time zone: UTC
0 0 * * * /usr/local/bin/my-job >> /var/log/my-job.log 2>&1
- OKRuns in the server’s local time zone. cronie (RHEL, Fedora) accepts a CRON_TZ= line above the job; Debian’s cron does not.
- Heads-upEscape % as \% in the command: an unescaped % ends the command and starts stdin.
- Heads-upcron runs with a minimal PATH and no login shell. Use absolute paths and redirect output, or failures disappear.
- Linux crontab docs ↗
Cron jobs failing silently?
I build background job systems with retries, alerting and dashboards, so you hear about failures before your customers do.
01
What 0 0 * * * means
Field by field:
| Field | Value | Matches |
|---|---|---|
| Minute | 0 | 0 |
| Hour | 0 | 0 |
| Day of month | * | any |
| Month | * | any |
| Day of week | * | any |
02
Gotchas
- Midnight is crowded everywhere. Moving to 0 3 * * * or an odd minute like 7 0 * * * avoids contention.
- On UTC platforms (GitHub default, Vercel, EventBridge rules), midnight UTC is 05:30 in India and 19:00/20:00 the day before in New York.
03
Does it run everywhere?
Checked against each platform's rules, assuming UTC:
| Platform | Verdict | Why |
|---|---|---|
| Linux crontab | Works, with a catch | Escape % as \% in the command: an unescaped % ends the command and starts stdin. |
| GitHub Actions | Works, with a catch | Runs at minute 0 are the most likely to be delayed or dropped under load. GitHub suggests another minute, e.g. 17. |
| Vercel | Works, with a catch | Vercel now labels Cron Jobs “legacy” in favour of Vercel Schedules, which add time zones. Existing crons keep working. |
| AWS EventBridge | Works | Six fields: the year is added at the end, and one of day-of-month / day-of-week must be ?. |
| Kubernetes | Works, with a catch | Without timeZone, the schedule uses the kube-controller-manager’s local zone. TZ= or CRON_TZ= inside schedule is rejected from v1.29. |
04
Questions engineers actually ask
What is the cron expression for midnight every day?
0 0 * * *, which is minute 0 of hour 0. @daily is the shortcut on Linux; GitHub Actions needs the five-field form.
Does 0 0 * * * run at the start or end of the day?
At the start: 00:00 is the first minute of the new day.
Why does my job run on days I didn't expect?
Probably the day-of-month / day-of-week OR rule. If both fields are set, cron runs when either matches. Set one of them to * to get the usual AND behaviour.
What time zone does cron use?
Whatever the scheduler uses: the server's zone for Linux cron, UTC for Vercel and EventBridge rules, UTC by default on GitHub Actions (with an optional timezone key) and the controller's zone on Kubernetes unless spec.timeZone is set.
05
Other schedules
- Every Minute
* * * * * - Every 2 Minutes
*/2 * * * * - Every 5 Minutes
*/5 * * * * - Every 10 Minutes
*/10 * * * * - Every 15 Minutes
*/15 * * * * - Every 30 Minutes
*/30 * * * * - Every Hour
0 * * * * - Every 2 Hours
0 */2 * * * - Every 3 Hours
0 */3 * * * - Every 6 Hours
0 */6 * * * - Every 12 Hours
0 */12 * * * - Twice a Day
0 9,21 * * * - Every Day at 9am
0 9 * * * - Every Day at Noon
0 12 * * * - Every Weekday
0 0 * * 1-5 - Every Weekday at 9am
0 9 * * 1-5 - Every Weekend
0 0 * * 6,0 - Every Monday
0 0 * * 1 - Every Friday at 5pm
0 17 * * 5 - Every Sunday at Midnight
0 0 * * 0 - Every Week
0 0 * * 0 - Every 15th of the Month
0 0 15 * * - First Day of the Month
0 0 1 * * - Last Day of the Month
0 0 28-31 * * - Every Month
0 0 1 * * - Every Quarter
0 0 1 1,4,7,10 * - Every Year
0 0 1 1 * - Every Hour During Business Hours
0 9-17 * * 1-5 - Every 30 Minutes During Business Hours
*/30 9-17 * * 1-5
Or build your own in the cron expression builder.
06
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Fine print
Tools: on the house.
Engineer: by the hour.
Infra that doesn't page you at 3am costs a little more. I build background job systems with retries, alerting and dashboards.
I'm Himanshu, an AI and full-stack engineer. I build MVPs, AI agents and the growth plumbing around them for early-stage startups.