Cron Expression Explainer

This tool translates a cron expression into plain English, so you can understand exactly when a scheduled job will run without deciphering the cryptic syntax. Cron is the time-based scheduler used on Unix and Linux systems, and in countless tools and cloud platforms, to run tasks automatically: backups overnight, reports every Monday, cleanups every few minutes. Schedules are written as a terse line of five fields, covering the minute, hour, day of the month, month, and day of the week, each able to hold a single value, a list, a range, a step, or a wildcard. The syntax is powerful but famously hard to read at a glance, and a small mistake can mean a job runs far too often, or never. This tool removes the guesswork. You enter the five fields of your cron expression, and the calculator describes in everyday language when the schedule fires, and breaks down what each field means. The result updates as you type, so you can adjust a field and immediately confirm the effect. Use it to check a schedule before you deploy it, to understand an existing crontab you have inherited, or to learn the syntax by experimenting. The five fields, in order, are minute (0 to 59), hour (0 to 23), day of month (1 to 31), month (1 to 12), and day of week (0 to 6, where 0 is Sunday). An asterisk means every value, a slash sets a step such as every fifth minute, a hyphen gives a range, and a comma gives a list. Getting a schedule right the first time saves a lot of trouble later.

Five fields: minute, hour, day-of-month, month, day-of-week. * = every, */n = step, a-b = range, a,b = list. Describes common patterns in plain English.