Cron Expression Generator/Parser
Parse a standard cron expression into a plain-English description and its next 5 actual run times — computed exactly, accounting for month lengths and daylight saving transitions, using the cron-parser and cronstrue libraries. Fields are read in your local timezone, the same way a real crontab would interpret them. Includes presets for common schedules. Runs entirely client-side — nothing is uploaded.
Next 5 run times
The expression's fields are read in your local timezone, same as a crontab running on this device.
- Sat, Sep 26, 2026, 05:05 AM UTC
- Sat, Sep 26, 2026, 05:10 AM UTC
- Sat, Sep 26, 2026, 05:15 AM UTC
- Sat, Sep 26, 2026, 05:20 AM UTC
- Sat, Sep 26, 2026, 05:25 AM UTC
About this tool
This tool parses a standard 5-field cron expression (minute hour day-of-month month day-of-week, optionally with a leading seconds field) into a plain-English description and its next 5 actual run times. Cron's syntax has real sharp edges — step values (*/5), ranges (1-5), lists (1,15,30), and the interaction between day-of-month and day-of-week (a schedule with both set fires when either matches, not both) — which this tool computes exactly rather than approximates, correctly accounting for month lengths and daylight saving transitions. The expression's fields are read in your local timezone, the same way a crontab running on this device would interpret them. It runs entirely client-side — nothing you type is ever sent anywhere.
What you can do
- Plain-English description of any cron expression, live as you type
- The next 5 actual run times, computed exactly (DST and month-length aware)
- Common presets for the schedules people write most often
- Nothing is uploaded — parsing happens locally in your browser
How to use
Step 1
Enter a cron expression
Type your own 5-field expression, or click a preset to start from a common schedule.
Step 2
Read the description
A plain-English translation of what the expression means.
Step 3
Check the next run times
The next 5 times it would actually fire, computed in your local timezone.
Example
This expression:
Cron
0 9 * * 1-5
describes as "At 09:00 AM, Monday through Friday" — the 1-5 range in the weekday field means Monday (1) through Friday (5).
How your data is handled
This tool is labeled 🟢 Browser: your cron expression is parsed directly in your browser using the cron-parser and cronstrue libraries — nothing is uploaded to a server, and nothing about it is retained once you leave the page.
Frequently asked questions
What do the 5 fields mean?+
In order: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-6, where 0 is Sunday). An optional 6th field, if present, comes first and represents seconds.
What happens if I set both day-of-month and day-of-week?+
They're OR'd together, not AND'd — "0 0 1 * 1" runs on the 1st of the month AND every Monday, not only when the 1st happens to fall on a Monday. This is standard cron behavior, not specific to this tool.
What timezone are the run times shown in?+
Your browser's local timezone — the expression's fields are interpreted the same way a crontab running on this device would interpret them, and daylight saving transitions are accounted for automatically.
Why does it say my expression is invalid?+
Most often a wrong field count (a valid expression needs exactly 5 fields, or 6 with a leading seconds field) or a value outside that field's valid range, like 99 in the hour field.
Is my cron expression uploaded anywhere?+
No — it's parsed and evaluated directly in your browser using the cron-parser and cronstrue libraries. Nothing here ever leaves your device.