Cron Parser
Read any cron expression in plain words.
Plain words
Next 5 runs
Field by field
About Cron Parser
A cron parser turns a cron expression into a sentence you can read. Paste a value like */15 * * * * and this tool tells you it runs every 15 minutes, lists the next five times it will fire, and expands each of the five fields into the numbers it actually covers. It accepts the forms you meet in real crontabs: day and month names such as mon-fri and jan-mar, steps like 1-20/6, lists like 15,45, and the @daily family of shortcuts. Everything runs in your browser, so an expression that contains an internal hostname or a path stays on your screen.
How to Use Cron Parser
Paste or pick a cron expression
Type or paste the expression into the Cron expression box. The text updates as you type. You can also click one of the preset chips such as Weekdays or Hourly to load a common schedule.
Read the plain words and next runs
The Plain words card states the schedule in a sentence. The Next 5 runs card lists the next five fire times with the gap from now, such as in 2 days, so you can check the timing before you install it.
Check each field
The Field by field card shows what every field resolves to. * becomes every day, while 1-5 expands to the five days it covers. This is where you spot a day-of-week or day-of-month mix-up.
Copy it into your scheduler
Click Copy sentence to paste the explanation into a ticket, or Copy crontab line to get the expression with a /path/to/script.sh placeholder ready to paste into a crontab file.
Why Use Cron Parser: Common Use Cases
Reviewing someone else's cron job
When a schedule is inherited from a colleague or an old server, paste it in and read the sentence instead of counting fields by hand.
Checking a systemd timer conversion
Compare a systemd OnCalendar= expression with the crontab form you need before switching a job between the two schedulers.
Debugging a job that never fires
Field by field output reveals a day-of-week value that skips weekends, or a day-of-month value that never reaches 31 and so misses short months.
Writing runbook documentation
The plain words sentence gives you a line that non-technical teammates can read in an operations document.
Cron Parser Specifications
| Input Formats | Cron expression text |
|---|---|
| Output Formats | Plain words sentence, Next run times, Expanded field values |
| File Size Limit | No strict limit (dependent on device memory) |
| Processing Engine | 100% Client-side (Runs locally in your browser) |
| Data Retention | Files never leave your device |
| Batch Processing | Single file processing |
Tips for Cron Parser
Not sure what a Unix timestamp means next to your schedule? Convert it with Timestamp Converter.
Two schedules that look different in the crontab can fire at the same moment. Write both down as sentences and compare them here.
In a crontab, a schedule that never matches any date is silently skipped by cron. Always confirm the next runs list is not empty.
The tool reads 5 fields by default. Tick Read as 6 fields (with seconds) for schedulers such as Quartz or Spring cron that put seconds first.
To see what changed between two versions of a config file, paste both sides into Diff Checker.
Frequently Asked Questions
What does the cron expression */15 * * * * mean?
It runs every 15 minutes of every hour, so 24 runs a day. The first field is the minute, and */15 matches minutes 0, 15, 30, and 45. The parser states this as a sentence and shows the next five fire times so you can confirm the cadence before saving it.
Why is my day of month and day of week both set?
Cron uses an OR rule for that pair, not AND. When both fields are restricted, a run happens if the day of month matches OR the day of week matches. That is why 0 0 13 * 5 fires on the 13th of every month and also on every Friday, which surprises people who expect an AND.
Can I use names like MON or JAN in a cron expression?
Yes. Day names accept three letters such as mon, tue, and sun, and month names work the same way with jan through dec. Ranges also work in name form, so mon-fri and jan-mar parse exactly like their numeric equivalents.
What is the difference between 0 and 7 for Sunday?
They mean the same day. Cron allows both 0 and 7 for Sunday, which is why you often see @weekly written as 0 0 * * 0 on one system and 0 0 * * 7 on another. This parser treats both as Sunday.
Why does the parser reject @reboot?
Because @reboot has no schedule. It runs once when the machine starts, at a moment that has no date or time you can predict, so there is no next run to show. The parser says so instead of pretending the expression is invalid.
Is this cron parser free to use?
Yes, with no account and no upload step. The parsing happens in your browser, so an expression that contains an internal hostname or a script path is never sent anywhere. There is no limit on how many expressions you check.