How to use Cron
- 1. Build or decode. Pick a rhythm, or paste an expression.
- 2. Read English. See what the schedule means in one sentence.
- 3. Preview runs. Next five times plus days that fire this month.
- 4. Export. Copy the expression or a systemd OnCalendar line.
About this tool
Cron looks like line noise until a job misses Monday. This suite lets you build a schedule from presets and weekday taps, or paste an expression and see plain English, the next five runs, and a calendar of fire days — all in this tab, nothing scheduled on a server.
Build vs decode
Build mode starts from common rhythms (every 5 minutes, weekdays at 9:00) and fine-tunes minute, hour, day, month, and weekday. Decode mode is for expressions you already have.
Fields
Standard five-field cron is minute hour day-of-month month day-of-week. Optional six-field expressions with seconds are accepted when decoding.
Timezone
Next runs use this browser’s clock. Your server’s TZ still wins in production — pair with the timezone explorer when DST is involved.
Code examples
weekdays 9am
0 9 * * 1-5