Cron Expression Parser & Generator

About Cron Expression Parser

A cron expression compresses a schedule into five fields: minute, hour, day of month, month and day of week. The syntax is compact enough to write quickly but cryptic enough that reviewing it later requires care, especially when day of month and day of week are combined, because those fields are combined with OR rather than AND.

This parser describes each field in plain English, flags the values it found, and computes the next run times from your current timezone. A generator mode covers the schedules that appear in practice most often, from every five minutes to the first weekday of the month.

How it works

• The expression is validated field by field, including ranges, steps and lists.
• Each field is translated into a short human description.
• The next run times are computed by advancing minute by minute through the calendar.
• Day of month and day of week are combined with OR semantics, as the cron specification requires.
• Generator mode produces standard expressions for common schedules such as hourly, nightly and weekly.
• Named values such as JAN, SUN and MON are accepted alongside numbers.

Input and output

Privacy

Parsing and schedule computation run entirely in your browser.