What is a cron expression?
A cron expression is a string of numbers and symbols used to schedule tasks to run automatically at specific times.
What is crontab?
Crontab is a file where cron jobs (scheduled tasks) are defined. Each user on a system can have their own crontab.
What is a cron job?
A cron job is a command or script scheduled to run at specific times or intervals using cron.
What are the five fields in a cron expression?
Minute, hour, day of month, month, and day of week.
How do I open my crontab file?
Use the command crontab -e in the terminal to edit your cron jobs.
How do I see current cron jobs?
Type crontab -l to list your existing cron jobs.
How often can cron jobs run?
They can run as often as once every minute.
What does * * * * * mean?
It means the job will run every minute.
*What does /5 * * * * mean?
It means the job will run every 5 minutes.
Can I use ranges like 1-5 in cron expressions?
Yes, for example, 1-5 in the day of week field means Monday through Friday.
What does 0 0 * * 0 mean?
It runs at midnight every Sunday.
Can cron jobs run multiple times per hour?
Yes, you can use values like */15 to run every 15 minutes.
Can I run cron jobs every few seconds?
Standard cron does not support seconds. It runs at most once per minute.
Can I run multiple commands in one cron job?
Yes, separate them with &&, ;, or &&.
How do I run a script in crontab?
Use the full path to the script in your cron expression, like /usr/bin/python3 /home/user/myscript.py.
What time format does cron use?
It uses 24-hour time format.
Can I use names like Mon or Jan in cron?
Yes, most systems accept short names like Mon for Monday or Jan for January.
What does 0 0 1 * * mean?
It runs at midnight on the first day of every month.
What’s the difference between cron and crontab?
Cron is the system that runs scheduled tasks. Crontab is the file where those tasks are defined.
Can I comment out a line in crontab?
Yes, just add a # at the beginning of the line.
How do I remove a cron job?
Edit your crontab with crontab -e and delete the line you don’t want.
What is Cron Guru?
Cron Guru is a free online tool to help you create and understand cron expressions easily.
Is Cron Guru free to use?
Yes, it is completely free with no sign-up required.
Can I generate random cron expressions with Cron Guru?
Yes, Cron Guru has a feature to create random cron schedules for testing or exploring.
How can I understand what a cron expression means?
Paste your expression into Cron Guru and get a plain-English explanation.
Does Cron Guru show the next run time?
Yes, it tells you when the next execution will happen.
Can I copy cron expressions from Cron Guru?
Yes, just click and copy them directly to your clipboard.
Is Cron Guru accurate for Linux systems?
Yes, it generates standard cron expressions used in most Linux environments.
Do I need to install anything to use Cron Guru?
No, it works fully in your web browser.
Can I use Cron Guru for WordPress tasks?
Yes, you can generate cron schedules for use with WordPress plugins or wp-cron.
Does Cron Guru work on mobile devices?
Yes, the site is mobile-friendly and responsive.
Can I run a cron job only on weekdays?
Yes, use * * * * 1-5 to run from Monday to Friday.
Can I run a job every hour between 9 AM and 5 PM?
Yes, use 0 9-17 * * *.
Can I run a cron job twice a day?
Yes, you can schedule it at specific hours like 0 9,17 * * *.
What happens if Day of Month and Day of Week are both set?
The job runs when either field matches unless your system uses specific rules (check your environment).
Can cron run on specific days only?
Yes, you can set exact days using the day of week or day of month fields.
Can I back up files with cron?
Yes, just schedule your backup script with a cron job.