Build, explain and validate cron schedules visually — see next run times and human-readable descriptions instantly.
| Symbol | Meaning | Example |
|---|---|---|
* | Any / every value | * * * * * — every minute |
, | List of values | 1,15,30 — at 1, 15 and 30 |
- | Range of values | 1-5 — 1 through 5 |
/ | Step values | */5 — every 5 units |
| Field | Range | Allowed Values |
|---|---|---|
| Minute | 0–59 | Numbers, *, , - / |
| Hour | 0–23 | Numbers, *, , - / |
| Day of Month | 1–31 | Numbers, *, , - / |
| Month | 1–12 | Numbers or JAN–DEC |
| Day of Week | 0–7 | Numbers or SUN–SAT (0 & 7 = Sunday) |
Every cron expression has five space-separated fields: minute (0–59), hour (0–23), day of month (1–31), month (1–12), and day of week (0–7). The scheduler fires when all five conditions match simultaneously.
The asterisk (*) means "any value". A slash (/5) creates steps — e.g. run every 5 minutes. A hyphen (1-5) defines a range, and commas (1,15) create a list of specific values.
Cron is used for database backups, sending scheduled emails, clearing caches, running report generation, checking for updates, and any task that needs to run on a predictable recurring schedule on Unix/Linux servers.