A cronjob is a task that runs automatically at fixed times on your server, such as sending newsletters, cleaning up temporary files, or running a script from a WordPress plugin. In Plesk, you set this up via the ‘Scheduled Tasks’ section. You don’t need to be a developer to do this yourself: in this article, we’ll walk step by step through how to create a cronjob, what the time notation means, and how to check whether your task is really working.
What is a cronjob and when do you need one
Normally, something only happens on your website when a visitor opens a page. However, some tasks need to run in the background, regardless of whether there are visitors. Think of:
- Automatically backing up your database
- Performing WordPress tasks that are normally triggered by visitors (replacing WP-Cron with a real cronjob)
- Cleaning up expired sessions or temporary files
- Sending reports or emails at a fixed time
- Synchronizing stock or prices with an external party
A cronjob is therefore nothing more than an agreement with the server: ‘execute this command or script, at this time, every time again’.
A cronjob runs automatically at the set time, without anyone needing to visit the website.
Creating a cronjob in Plesk
Creating a cronjob in Plesk is straightforward and requires no terminal knowledge.
Log in to Plesk
Go to your Plesk environment and log in with your account details.
Open ‘Scheduled Tasks’
Choose the domain for which you want to set up a cronjob and open the ‘Scheduled Tasks’ section (also called Cron Jobs).
Click ‘Add Task’
Choose whether you want to call a PHP script, a shell command, or a URL (useful for WordPress cron replacements).
Set the time
Fill in the minute, hour, day, and month, or choose one of the default options such as ‘every day’ or ‘every hour’.
Save the task
Click ‘OK’ to activate the task. You can then view the execution logs to check whether the script runs without errors.
Cronjob time notation explained
Cronjobs work with five time fields: minute, hour, day of the month, month, and day of the week. Plesk usually displays this as separate fillable fields, but it helps to understand the logic:
- Minute: 0 to 59
- Hour: 0 to 23
- Day of the month: 1 to 31
- Month: 1 to 12
- Day of the week: 0 (Sunday) to 6 (Saturday)
An asterisk (*) means ‘every possible value’. For example, if you want to run a script every night at 03:00, you fill in: minute 0, hour 3, and an asterisk for the rest. If you only want this on Monday, you set a 1 in ‘day of the week’.
Pay attention to the difference between ‘every 30 minutes’ and ‘every half hour on the full and half hour’. In Plesk, you can often choose between an interval or fixed times; choose consciously what you need, as this makes a difference for scripts that depend on each other.
Common mistakes and checking if it works
The most common problems with cronjobs are easy to prevent:
- Incorrect path to the script: always use the full, absolute path, not a relative path.
- Script expects input from a browser: a cronjob runs without a session or cookies, so scripts that depend on these sometimes don’t work as expected.
- Running too often: running a heavy task every minute can affect server performance. Choose a realistic frequency.
- No error handling: have the script write results or errors to a log file, so you can see whether the task was actually executed.
After setting up, always check the execution logs in Plesk. If you don’t see any execution, first check whether the time has already passed and whether the path to the script is correct.
Frequently Asked Questions
Can I set up multiple cronjobs at the same time?
Yes, you can create as many scheduled tasks as needed. However, make sure that heavy tasks don’t all run at the same time, to prevent peaks in server load.
Does a cronjob work even if nobody visits the website?
Yes, that’s precisely the advantage of a cronjob compared to, for example, WordPress’ default WP-Cron system, which depends on visitor traffic.
Can I temporarily disable a cronjob without deleting it?
In Plesk, you can often set a scheduled task to ‘inactive’ instead of deleting it, so you keep the settings for later.
Where do I find Plesk if I host with Tandata?
You log in with your account details to the Plesk environment that comes with your web hosting. If you can’t figure it out, the support team is happy to help you via the knowledge base or direct contact.
Conclusion
Cronjobs are a powerful tool for automatically running recurring tasks, without you having to keep an eye on them yourself. In Plesk, you set this up easily via ‘Scheduled Tasks’, where you choose between a script, command, or URL. Pay close attention to the time and frequency, and always check the execution logs to see if everything works as intended. Are you unsure about your current hosting environment or want to switch to a provider with Plesk and 24/7 support? Then check out the options for web hosting.