Run a cron job twice a month
0 0 1,15 * *
Check it below, then take the line for any of 17 schedulers.
Click to edit · paste a crontab line · hover a field for its values
At 00:00 on days 1 and 15 of the month.
Nothing to watch out for on Debian / Ubuntu cron.
# crontab -e (runs on the server's clock: UTC) 0 0 1,15 * * /path/to/command
· sudo runwisp takeover runs your crontab as it is · How RunWisp compares
Details
Upcoming runs
Calendar 24 days a year
Between two dates
Daylight saving
When things go wrong Server off: Skipped
- Server was off
- Skipped. anacron only catches up cron.daily, weekly and monthly.
- Last run still going
- Starts another copy on top.
- A run fails
- Output is mailed if MAILTO and a mail server work. No output, no mail, whatever the exit code.
- Time zone
- The server's zone. TZ= in a crontab only reaches the command.
- Precision
- 1 minute.
Sources: manpages.debian.org,manpages.debian.org
Other schedulers As written in 10 of 16
- ✓ cronie
0 0 1,15 * *vs RunWisp - ✓ BusyBox crond
0 0 1,15 * * - ↻ systemd timer
*-*-01,15 00:00:00 UTCsystemd timer uses OnCalendar=, not cron lines. vs RunWisp - ✓ RunWisp
0 0 1,15 * * - ✓ Kubernetes CronJob
0 0 1,15 * * - ≠ Ofelia
0 0 0 1,15 * *Ofelia puts seconds first, so it reads this as: at 01:00 and 15:00 every day. vs RunWisp - ✓ Dagu
0 0 1,15 * *vs RunWisp - ✓ PM2 cron_restart
0 0 1,15 * *vs RunWisp - ≠ Jobber
0 0 0 1,15 * *Jobber puts seconds first, so it reads this as: at 01:00 and 15:00 every day. vs RunWisp - ✓ GitHub Actions
0 0 1,15 * * - ✓ GitLab CI schedule
0 0 1,15 * * - ↻ AWS EventBridge Scheduler
cron(0 0 1,15 * ? *)AWS EventBridge Scheduler takes cron() with 6 fields, a year last, and ? in one day field. - ✓ Google Cloud Scheduler
0 0 1,15 * * - ✓ Jenkins
0 0 1,15 * * - ↻ Quartz
0 0 0 1,15 * ?Quartz takes 6 or 7 fields, seconds first, with ? in one day field. - ↻ Spring @Scheduled
0 0 0 1,15 * *Spring @Scheduled takes exactly 6 fields, seconds first.
✓ works as written · ↻ different syntax · ≠ runs at other times · ? not documented · ✗ can't
Twice a month, in every scheduler
Works as written in 11 of 17. Times are UTC; the checker above takes any zone.
- Runs in 2027
- 24
- Days with a run
- 24
- Longest gap
- 17 days
| Scheduler | Line | Notes | |
|---|---|---|---|
| Debian / Ubuntu cron | ✓ | 0 0 1,15 * * | Works as written. |
| cronie | ✓ | 0 0 1,15 * * | Works as written. |
| BusyBox crond | ✓ | 0 0 1,15 * * | Works as written. |
| systemd timer | ↻ | OnCalendar=*-*-01,15 00:00:00 UTC | systemd timer uses OnCalendar=, not cron lines. |
| RunWisp | ✓ | 0 0 1,15 * * | Works as written. |
| Kubernetes CronJob | ✓ | 0 0 1,15 * * | Works as written. |
| Ofelia | ≠ | 0 0 0 1,15 * * | Ofelia puts seconds first, so it reads this as: at 01:00 and 15:00 every day. |
| Dagu | ✓ | 0 0 1,15 * * | Works as written. |
| PM2 cron_restart | ✓ | 0 0 1,15 * * | Works as written. |
| Jobber | ≠ | 0 0 0 1,15 * * | Jobber puts seconds first, so it reads this as: at 01:00 and 15:00 every day. |
| GitHub Actions | ✓ | 0 0 1,15 * * | Works as written. |
| GitLab CI schedule | ✓ | 0 0 1,15 * * | Works as written. |
| AWS EventBridge Scheduler | ↻ | cron(0 0 1,15 * ? *) | AWS EventBridge Scheduler takes cron() with 6 fields, a year last, and ? in one day field. |
| Google Cloud Scheduler | ✓ | 0 0 1,15 * * | Works as written. |
| Jenkins | ✓ | 0 0 1,15 * * | Works as written. |
| Quartz | ↻ | 0 0 0 1,15 * ? | Quartz takes 6 or 7 fields, seconds first, with ? in one day field. |
| Spring @Scheduled | ↻ | 0 0 0 1,15 * * | Spring @Scheduled takes exactly 6 fields, seconds first. |
✓ works as written · ↻ different syntax · ≠ runs at other times · ? not documented · ✗ can't
Cron runs the line. Nobody tells you how it went.
RunWisp is an open-source cron replacement that ships as a single binary. It reads the same cron line and keeps a record of every run: output, exit code, duration.
# crontab -e (runs on the server's clock: UTC)
0 0 1,15 * * /usr/local/bin/job.sh [tasks.job]
cron = "0 0 1,15 * *"
timezone = "UTC"
run = '/usr/local/bin/job.sh' | cron | RunWisp | |
|---|---|---|
| The server was off at run time | Skipped. anacron only catches up cron.daily, weekly and monthly. | Runs the most recent missed run at start-up (catch_up = 1) and sends a missed-run alert. |
| The last run is still going | Starts another copy on top. | Queues it. on_overlap = "queue" is the default. |
| A run fails | Output is mailed if MAILTO and a mail server work. No output, no mail, whatever the exit code. | Marked failed and sent to your alert channels. retry_attempts adds retries. |
Keep your crontab. sudo runwisp takeover runs it where it is and retires cron,
crontab -e keeps working, and runwisp service uninstall puts cron
back. It needs Linux with systemd; elsewhere, runwisp import cron converts the
file. RunWisp doesn't do L, W or #, and it runs
on one machine, not a cluster.
Moving from cron →
Questions
What does 0 0 1,15 * * mean?
How do I run a job twice a month with a systemd timer?
OnCalendar=*-*-01,15 00:00:00 UTC. systemd timer uses OnCalendar=, not cron lines.How do I run a job twice a month in a Kubernetes CronJob?
0 0 1,15 * * works as written.How do I run a job twice a month in GitHub Actions?
0 0 1,15 * * works as written.How do I run a job twice a month on AWS EventBridge?
cron(0 0 1,15 * ? *). AWS EventBridge Scheduler takes cron() with 6 fields, a year last, and ? in one day field.Start in 30 seconds. Ship on your terms.
A single Go binary. If it doesn't earn the disk space, rm it. No account, no signup, no catch.
curl -fsSL https://get.runwisp.com | sh