Skip to content
ToolQivo

Cron Expression Parser

Read a cron expression in plain English and see when it next runs.

Developer Tools Reviews Free · no sign-up

Quick Tool Overview

The Cron Expression Parser reads an expression back in plain English, expands every field into the values it matches, and calculates the next run times — recognising six-field Quartz expressions and the shorthand forms.

What it does
Explains a cron expression and predicts its runs
You give it
A cron expression from anywhere
You get back
A description, expanded fields and the next runs
Best for
Understanding a schedule you inherited
Developer Tools Free, unlimited use No sign-up Runs in your browser

About the Cron Expression Parser

Paste an expression from a crontab, a CI config or a Kubernetes CronJob and read what it actually does. Each field is expanded into the full set of values it matches, so a step or a range stops being something you have to work out in your head.

The next run times are calculated rather than estimated, by stepping forward minute by minute and testing the expression — which is exactly what cron does. Six-field expressions from Quartz and Spring are recognised and the seconds field called out, month and day names are understood, the shorthand forms expand, and the day-of-month against day-of-week OR behaviour is flagged whenever an expression is exposed to it.

Key features of the Cron Expression Parser

Every field expanded

A range with a step becomes the actual list of values, so you are not working it out in your head.

Six-field expressions recognised

Quartz and Spring add a seconds field at the front, and pasting one into a crontab shifts everything by one. That is called out.

Names understood

JAN and MON work as well as 1 and 1, including inside ranges.

Next runs, really calculated

By stepping forward and testing the expression, which is what cron itself does — so the answer is right rather than plausible.

The OR behaviour flagged

Whenever both day fields are restricted, because that expression runs on either and almost nobody means it to.

How to use the Cron Expression Parser

  1. 1

    Paste the expression

    Five fields, six fields, or a shorthand such as @daily.

  2. 2

    Read the description

    What it does, in a sentence.

  3. 3

    Check each field

    Every value each field matches, expanded from its ranges and steps.

  4. 4

    See the next runs

    The next several times it fires, calculated from now.

Frequently asked questions

Because Quartz, Spring and a few other schedulers add a seconds field at the front. Standard Unix cron has five, so a six-field expression pasted into a crontab shifts everything by one.

Reviews of the Cron Expression Parser

What people who use the Cron Expression Parser think of it. Reviews come from visitors and are posted as written.

No ratings yet

Yours would be the first.

  • 5 0 reviews rated 5 stars
  • 4 0 reviews rated 4 stars
  • 3 0 reviews rated 3 stars
  • 2 0 reviews rated 2 stars
  • 1 0 reviews rated 1 star

Write a review

Used this tool? Your rating helps the next person decide.

Your rating

Plain text only — links, email addresses and HTML are not accepted. Your name and review are shown publicly; nothing else is collected. See the privacy policy.

0 reviews

Newest first

No reviews yet

Be the first to rate the Cron Expression Parser. It takes half a minute and no account.

Write the first review

More developer tools