cronlinuxscheduleautomation
Cron Jobs: The Complete Guide
What is crontab, cron expression syntax, example tasks, common errors and debugging tools.
Published February 23, 2026·Time to read: 8 min
What is cron?
Cron is a task scheduler in Unix/Linux that executes commands on a schedule. Configured via crontab (cron table).
Cron expression syntax
┌───────────── minutes (0-59)
│ ┌─────────── hours (0-23)
│ │ ┌───────── day of the month (1-31)
│ │ │ ┌─────── month (1-12)
│ │ │ │ ┌───── day of week (0-7, Sunday = 0 or 7)
│ │ │ │ │
* * * * * /path/to/command Special characters
| Symbol | Meaning | Example |
|---|---|---|
| --- | --- | --- |
| `*` | Any value | `* * * * *` - every minute |
| `,` | Enumeration | `1.15` - 1st and 15th |
| `-` | Range | `1-5` - from 1 to 5 |
| `/` | Step | `*/5` — every 5 units |
10 popular examples
# Every minute
* * * * *
# Every hour at :00
0 * * * *
# Every day at 00:00
0 0 * * *
# Weekdays at 9:00
0 9 * * 1-5
# On weekends at 12:00
0 12 * * 6.0
# Every 5 minutes
*/5 * * * *
# Once a month (1st at midnight)
0 0 1 * *
# Every quarter
0 0 1 1,4,7,10 *
# Twice a day
0 9.21 * * *
# Every 30 minutes from 9 to 18
*/30 9-18 * * * Check your cron schedule and see the next 5 runs.