CronTool
Cron expression editor & debugger

Cron Reader - translate any cron expression to plain English

Paste a cron expression and CronTool reads it back to you in plain English: “Every 15 minutes, on weekdays, between 09:00 and 17:59”. The next 30+ runs land on a live calendar, each field is decoded individually, and every wildcard, range and step is explained - no syntax knowledge required.
Cron strings are dense by design. A single character can flip a schedule from every Monday to every weekday. The cron reader exists so you don't have to translate the syntax in your head every time.

Examples

  • 018***
    Every day at 18:00
  • 0*/5***
    Every 5 hours
  • 018**1-5
    Weekdays at 18:00
  • 001**
    Once a month

Cheatsheet

FieldRequiredValues RangeWildcardsminuteYes0-59, - * / hourYes0-59, - * / day of monthYes1-31, - * / L W monthYes1-12, - * /day of weekYes0-7, - * / L

Calendar

View future cron matches in a calendar

May 2026

Showing next 1000 cron schedules

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What the cron reader shows

  • English description - derived from the same cronstrue library used by major schedulers. Example: `0 0 L * *` becomes “At 00:00, on the last day of the month”.
  • Calendar of next runs - the next 30+ scheduled fires plotted in a real month view. Spot weekend runs, holiday gaps, and end-of-month anomalies instantly.
  • Field-by-field decode - each field shows what it accepts and what your value resolves to.
  • Validation - invalid fields highlight in red with the parser error in plain English.
  • Shareable link - copy a URL with the cron pre-filled to share the decoded view with your team.

Common cron expressions, decoded

  • * * * * * - Every minute.
  • */5 * * * * - Every 5 minutes.
  • */15 * * * * - Every 15 minutes.
  • 0 * * * * - Every hour, on the hour.
  • 0 0 * * * - Every day at midnight.
  • 0 9 * * 1-5 - Every weekday at 09:00.
  • 0 0 1 * * - On the 1st of every month at midnight.
  • 0 0 L * * - On the last day of every month at midnight (Quartz / AWS / robfig).
  • 0 0 1,15 * * - On the 1st and 15th of every month at midnight.
  • 30 8,17 * * * - At 08:30 and 17:30 every day.

See more in the full cron index or click any of these examples to view them on the calendar.

Cron reader vs cron builder

The cron reader takes an existing expression and explains it. The cron builder goes the other way - you pick the cadence, day, hour, and minute from inputs and CronTool composes the cron string. Use the reader when you have a string from a colleague, a docs page, or a legacy job; use the builder when you're writing one from scratch.

For decoding multiple cron expressions at once (a whole crontab file), the multi-cron visualizer lets you upload crontab -l output and see every schedule on the same calendar.

Supported cron dialects

The reader accepts the standard Unix 5-field syntax plus extended dialects:

  • Unix crontab (* * * * *)
  • AWS EventBridge / Lambda Scheduled (* * * * ? *)
  • Vercel cron jobs (5 fields, UTC)
  • Quartz Scheduler (6-7 fields with seconds and year)
  • robfig/cron, node-cron, rufus-scheduler, ncrontab, dragonmantank/cron-expression

Toggle the extended-cron switch at the top of the page to enable seconds, year and the ? / L / W / # modifiers.

Frequently asked questions

How does the cron reader work?

CronTool parses each field of your cron string, runs it through the same expression library used in production schedulers, and translates the result into an English sentence using cronstrue. It also computes the next runs and projects them onto a real calendar so you can verify the meaning visually.

What does each field of a cron expression mean?

Standard cron has 5 fields: minute (0-59), hour (0-23), day-of-month (1-31), month (1-12 or JAN-DEC), day-of-week (0-7 or SUN-SAT). Extended cron (Quartz, AWS EventBridge) adds an optional seconds field at the start (0-59) and an optional year field at the end (1970-3099).

What do *, /, ,, and - mean in a cron expression?

`*` is a wildcard - matches every value in the field. `,` is a list separator - `1,15,30` matches three values. `-` is a range - `9-17` matches every value from 9 through 17. `/` is a step - `*/15` means every 15th value starting from 0 (so 0, 15, 30, 45 in a 0-59 field).

What do L, W, ?, and # mean?

`L` is 'last' - last day of month, last weekday, etc. `W` is 'nearest weekday'. `?` means 'no specific value' and is used to resolve the day-of-month vs day-of-week conflict in Quartz / AWS. `#` selects the Nth weekday of the month - `2#1` is the first Monday. These are not in standard Unix cron - only in Quartz, AWS EventBridge, robfig/cron and similar.

How can I translate a cron expression to plain English?

Paste it into CronTool's reader. The translation appears immediately under the field grid (e.g. `0 9 * * 1-5` → 'At 09:00, Monday through Friday'). The reader supports list, range, step and alias syntax across standard, AWS, Vercel and Quartz dialects.

Can the reader decode extended cron expressions?

Yes - toggle the extended-cron switch in the top bar to enable seconds and year fields plus the `?`, `L`, `W` and `#` modifiers. The reader auto-detects 5/6/7-field expressions when you paste them.

Ready to schedule it?

Point Crontap at any URL. Pick any cron. Done.

WordPress, Shopify, Railway, Cloud Run, Vercel, HubSpot, Ghost, your own box. If it answers HTTP, Crontap can drive it on a clock you can read, in the timezone that actually matters, and page you when something breaks.

Get startedSee examples

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Your next schedule
GET/wp-cron.php?doing_wp_cron=1

Schedule

“every 5 minutes”

Next run

in 23s

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