Cron Expression Builder

Build, decode, and humanize cron expressions across four dialects — Standard (Unix/Vixie), AWS EventBridge cron(), AWS EventBridge rate(), and Quartz. See the next firing times in your timezone.

This is a reference tool. For production schedules, always double-check semantics against your scheduler's official documentation — small dialect differences (e.g. EventBridge's 1=Sunday vs Unix's 0=Sunday) can shift firings by a full day.

How cron syntax works

Standard cron has five fields: minute, hour, day-of-month, month, day-of-week. Each accepts * for any value, comma-separated lists, hyphen ranges, and */N step values.

Dialect differences at a glance

Standard: 5 fields, day-of-week is 0-7 with both 0 and 7 meaning Sunday.
EventBridge cron(): 6 fields (adds year), day-of-week is 1-7 with 1=Sunday. Requires exactly one of day-of-month / day-of-week to be ?.
EventBridge rate(): simple recurring interval, e.g. rate(5 minutes).
Quartz: 6 or 7 fields. Adds a seconds field at the front and an optional year at the end. Same ?/L/W/# rules as EventBridge.

Cron Expression Builder

Dialect

Mode

Expression

Build

Decode

Next occurrences

How cron syntax works

Dialect differences at a glance