Cron Expression Parser
Translate cron expressions into plain English.
About Cron Expression Parser
Cron is a time-based job scheduler used in Unix-like operating systems. A cron expression is a compact string of five fields defining when a scheduled task should run: minute, hour, day of month, month, and day of week. This tool translates any valid cron expression into plain English and breaks down each field so you can understand the schedule at a glance. All processing happens in your browser.
FAQ
- What is a cron expression?
- A cron expression is a string of 5 space-separated fields that define a recurring schedule: minute, hour, day of month, month, and day of week.
- What does * mean in cron?
- An asterisk (*) means "every" — for example, * in the hour field means every hour.
- What is @daily?
- @daily is a shorthand for 0 0 * * * — midnight every day.
- What does */5 mean?
- The / operator means "every N" — */5 in the minute field runs every 5 minutes.
ABOUT THIS TOOL
Enter a cron expression - the five or six field string like 0 9 * * 1-5 that schedules jobs on Unix systems, CI pipelines, and job schedulers - and get a plain-English description of exactly when it fires, plus a list of upcoming run times. Cron syntax packs minute, hour, day-of-month, month, and day-of-week into a compact format that's genuinely hard to read at a glance, especially with ranges, lists, and step values like */15 mixed in. This tool is useful for double-checking a schedule before deploying it, understanding a crontab entry someone else wrote, or learning cron syntax without memorizing the field order from scratch.
HOW TO USE
- Paste your cron expression into the input field.
- Read the plain-English translation of the schedule.
- Check the list of next run times to confirm they match what you expect.
- Adjust individual fields and re-check the output if the schedule isn't quite right.
- Copy the verified expression into your crontab, CI config, or scheduler.
COMMON USE CASES
- A developer double-checking a deployment pipeline's scheduled job before merging a CI config change.
- Someone inheriting a server and trying to understand what an existing crontab entry actually does before touching it.
- A developer setting up a recurring database backup and confirming it runs at 2 AM daily, not hourly.
- Someone translating a cron expression from a tool like Kubernetes CronJobs into a schedule a non-technical teammate can understand.
- A student learning cron syntax who wants immediate feedback on what each field combination produces.
TIPS & COMMON MISTAKES
- Day-of-month and day-of-week are OR'd together, not AND'd, when both are restricted - a common source of confusion, since 0 0 1 * 1 means midnight on the 1st OR every Monday, not the 1st only when it's a Monday.
- Some systems use a 6-field format with seconds, like Quartz or Spring schedulers, while standard Unix cron uses 5 fields - confirm which variant your target system expects.
- Step values like */5 in the minute field mean every 5 minutes starting from 0, not 5 evenly spaced times, which matters if you're aligning multiple jobs to run near each other.
- Cron runs in the system's local timezone unless configured otherwise, so a schedule that looks right can fire at an unexpected time if the server's timezone differs from yours.
MORE QUESTIONS
- What's the difference between a 5-field and 6-field cron expression?
- Standard Unix and Linux cron uses 5 fields for minute, hour, day-of-month, month, and day-of-week, while schedulers like Quartz or Spring add a seconds field at the front for 6 fields total - check which format your target scheduler expects before pasting one in unmodified.
- How does cron handle a schedule where both day-of-month and day-of-week are restricted?
- It treats them as an OR condition rather than AND, so the job runs whenever either restricted field's condition is true, which is a frequent source of scheduling bugs.
- Can cron expressions handle things like the last day of the month or every other Tuesday?
- Standard cron syntax can't express these directly since it has no concept of relative or last-day logic - some extended implementations support a special L character for last day, but that's a non-standard extension, not universal cron syntax.
- What happens if a scheduled time doesn't exist, like during a daylight saving time transition?
- Behavior depends on the specific cron implementation and system clock handling - some skip the job, others run it at the nearest available time - so schedules near DST transitions deserve extra caution and testing.