Looking at 0 9 * * 1-5 and wondering when it runs? A cron expression explainer translates the cryptic syntax into plain English — "Every weekday at 9:00 AM."
This guide covers how cron expressions work, common patterns, and how to debug schedule logic.
Decode Any Cron Expression — Free
See plain English translation and next 10 execution times.
Cron 5-Field Format
* * * * *
| | | | |
| | | | +- Day of week (0-7)
| | | +-- Month (1-12)
| | +--- Day of month (1-31)
| +---- Hour (0-23)
+----- Minute (0-59)Common Expressions Decoded
| Expression | Meaning |
|---|---|
* * * * * | Every minute |
*/5 * * * * | Every 5 minutes |
0 9 * * * | Every day at 9:00 AM |
0 0 * * 0 | Every Sunday at midnight |
0 9 * * 1-5 | Every weekday at 9:00 AM |
0 0 1 * * | 1st of every month at midnight |
0 14 * * 0,6 | Saturday and Sunday at 2:00 PM |
30 8-17 * * 1-5 | Weekdays, 8:30 AM to 5:30 PM |
Special Characters
| Char | Meaning |
|---|---|
| * | Every value |
| , | List (1,5,15) |
| - | Range (1-5) |
| / | Step (*/5 = every 5) |
| @yearly | 0 0 1 1 * |
| @monthly | 0 0 1 * * |
| @weekly | 0 0 * * 0 |
| @daily | 0 0 * * * |
| @hourly | 0 * * * * |
Debugging Cron
When cron isn't firing as expected:
- Use explainer to verify schedule meaning
- Check next 5-10 execution times
- Verify time zone (cron uses server time)
- Confirm cron daemon is running
- Check cron logs (/var/log/cron)
- Verify command path (cron has minimal PATH)
How to Use the Tool (Step by Step)
- 1
Paste Cron Expression
Like 0 9 * * 1-5.
- 2
See Plain English
Tool decodes immediately.
- 3
View Next Runs
Tool shows next 5-10 execution times.
- 4
Verify Intent
Compare to what you wanted.
- 5
Adjust If Needed
Use cron generator for new expression.
Frequently Asked Questions
Why does my cron not run on Sunday?+−
Check day-of-week field. 0 = Sunday in standard cron, 7 = Sunday in some systems. Use 0 to be safe.
Cron uses 0-indexed or 1-indexed days?+−
Day of week: 0-7 (0 and 7 both = Sunday). Months: 1-12 (1 = January).
Can I have job run only on Christmas?+−
Yes: <code>0 0 25 12 *</code> — December 25 at midnight.
What time zone does cron use?+−
Server's local time zone. Set TZ environment variable in crontab to override.
Why might cron skip jobs during DST?+−
During DST transitions, some hours occur twice or are skipped. Cron handles this differently per system. Avoid scheduling at 2-3 AM.
Can I have multiple jobs at same time?+−
Yes — list them on separate lines. They'll run simultaneously.
Decode Any Cron Expression — Free
See plain English translation and next 10 execution times.
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