Cron.Explain is a free online cron expression decoder and explainer tool built for developers. Paste any 5-field cron expression and instantly receive a plain-English sentence describing the schedule, a breakdown of what each field means, and the next 5 exact dates and times the cron job will fire — calculated in your local timezone. No account, no install, no cost.
A cron expression is a string of 5 space-separated fields used to define a recurring schedule for automated tasks. Cron jobs are commonly used in Linux systems, CI/CD pipelines, cloud functions, and server automation. The 5 fields are: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-6, where Sunday is 0).
Each of the 5 cron fields supports special characters:
Asterisk (*) — matches any value in the field (wildcard)
Slash (/) — defines a step value. */15 means every 15 units.
Hyphen (-) — defines a range. 1-5 means 1 through 5.
Comma (,) — defines a list. 1,3,5 means 1, 3, and 5.
* * * * * — runs every minute of every day
0 * * * * — runs at minute 0 of every hour (every hour)
0 0 * * * — runs at midnight every day
0 9 * * 1-5 — runs at 9:00 AM Monday through Friday
*/15 * * * * — runs every 15 minutes
0 0 1 * * — runs at midnight on the first day of every month
0 0 * * 0 — runs at midnight every Sunday
30 18 * * 5 — runs at 6:30 PM every Friday
0 */6 * * * — runs every 6 hours
0 9,17 * * 1-5 — runs at 9:00 AM and 5:00 PM on weekdays
Cron.Explain provides a free REST API for decoding cron expressions programmatically. Send a POST request with your cron expression to /api/explain and receive a plain-English explanation, a field-by-field breakdown, and the next 5 scheduled run times as ISO 8601 timestamps. No API key required.
What does a cron expression look like? It has 5 fields: minute hour day-of-month month day-of-week.
What is */15 in a cron expression? It means every 15 minutes.
What does 0 9 * * 1-5 mean? At 9:00 AM, Monday through Friday.
What does * * * * * mean? Every minute of every day.
How do I schedule a cron job monthly? Use 0 0 1 * * to run at midnight on the 1st of every month.
Is this cron expression decoder free? Yes, Cron.Explain is completely free with no sign-up required.