A cron expression generator helps you build the five-field scheduling strings used by cron daemons on Linux and Unix systems. Instead of memorizing syntax like */5 * * * *, you can use the visual builder below to select minute, hour, day, month, and weekday values, then copy the resulting expression directly into your crontab. The tool also parses existing expressions so you can understand schedules written by others.
Every minute
Next 5 Execution Times
Common Presets
Visual Builder
Minute
0 - 59Hour
0 - 23Day of Month
1 - 31Month
1 - 12Day of Week
0 (Sun) - 6 (Sat)How to Use This Cron Expression Generator
A cron expression is a compact five-field string that tells a cron daemon when to run a scheduled task.
The five fields, from left to right, represent minute (0-59), hour (0-23),
day of month (1-31), month (1-12), and day of week (0-6, where 0 is Sunday).
Each field accepts a number, an asterisk (*) meaning "every," a slash
(/) for step values, a hyphen (-) for ranges,
and commas (,) for lists.
To build an expression using this tool, start with the Visual Builder below the output panel.
Each of the five cron fields has a dropdown where you choose a mode: "Every" sets the field to *,
"Every Nth" creates a step like */5, "Specific values" lets you pick individual numbers, and "Range"
creates a continuous span like 9-17. As you adjust any field, the generated cron expression and its
human-readable description update in real time at the top of the page.
If you already have a cron expression, paste or type it directly into the output field at the top. The visual builder will automatically update to reflect the parsed expression, making it easy to understand what an existing cron schedule does. The parser handles all standard notation including steps, ranges, and comma-separated lists.
The Next 5 Execution Times preview shows exactly when the cron job would fire next, calculated from your current local time. This helps you verify the expression does what you intend before deploying it to your server. Use the Common Presets to quickly load popular schedules like "Every 5 minutes," "Daily at midnight," or "Weekdays at 9 AM," then customize further if needed.
When your expression is ready, click the Copy button to place it on your clipboard. Then open
your terminal, run crontab -e, and paste the expression followed by a space
and the command you want to run. Save the file and your cron job is live. This tool works entirely in your browser
with no data sent to any server, so you can use it for sensitive scheduling tasks with complete privacy.
For a detailed walkthrough, see our guide: Cron Scheduling Guide: How Cron Expressions Actually Work.
FAQ
What is a cron expression?
A cron expression is a string of five fields separated by spaces that defines a schedule for automated tasks (cron jobs) on Unix-like systems. The five fields represent minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-6, where 0 is Sunday). Special characters like * (every), / (step), - (range), and , (list) let you build complex schedules concisely.
How do I read a cron expression like */5 * * * *?
Read each of the five fields left to right: minute, hour, day of month, month, day of week. An asterisk (*) means every possible value. A slash (/) means a step — so */5 in the minute field means every 5 minutes. Therefore */5 * * * * means every 5 minutes, every hour, every day of the month, every month, every day of the week.
What is the difference between cron and crontab?
Cron is the daemon (background service) that runs scheduled tasks on Unix and Linux systems. Crontab (cron table) is the file or command used to create, view, and edit the list of scheduled tasks. Each line in a crontab file contains a cron expression followed by the command to run. You edit your crontab with the command crontab -e.
Can I schedule a cron job to run every 30 seconds?
Standard cron only supports minute-level granularity, so you cannot directly schedule a job every 30 seconds. A common workaround is to create two cron entries for the same command — one running every minute and another running every minute with a 30-second sleep delay before execution. Alternatively, use a process manager like systemd timers or a task queue that supports sub-minute scheduling.
What time zone do cron jobs use?
By default, cron jobs use the system's local time zone. On most Linux servers this is UTC, but it can vary. You can check with the timedatectl command or by reading /etc/timezone. Some cron implementations (like Vixie cron) support setting a CRON_TZ variable at the top of the crontab file to override the time zone for all jobs below it.