Cron jobs on Windows: Task Scheduler instead of cron

Setup

Step by step

1. Open Task Scheduler

   Press Windows key + R, type taskschd.msc and confirm. On the right under "Actions" choose Create Task…. The "Create Basic Task" wizard next to it does not ask for a repetition every few minutes.

2. Set name and user

   On the "General" tab you give the task a name. If it should also run while nobody is logged in, choose Run whether user is logged on or not. Windows then asks for the account's password when you save.

3. Schedule as a trigger

   On the "Triggers" tab you create a trigger with New…, for example "Daily" at 06:00. For an interval in minutes, also tick Repeat task every:, choose for example 5 minutes and below it "for a duration of: Indefinitely". Values other than the suggested ones can be typed straight into the field, such as 1 minute.

4. What gets executed

   On the "Actions" tab choose New… and "Start a program". "Program/script" holds the program, "Add arguments" the file. For a PHP script it looks like this:

   Program/script:   C:\php\php.exe
   Add arguments:    C:\scripts\export.php
   Start in:         C:\scripts

5. Calling an address

   If the task should only call an address, use curl.exe. According to Microsoft it ships with Windows 10 from build 17063, that is from version 1803. Write curl.exe with the extension: in Windows PowerShell 5.1, curl without it is an alias for Invoke-WebRequest.

   Program/script:   C:\Windows\System32\curl.exe
   Add arguments:    -fsS -m 60 https://your-domain.com/cron.php?key=…

6. Missed runs and sleep mode

   On the "Settings" tab, Run task as soon as possible after a scheduled start is missed makes up for a lost run. On the "Conditions" tab, Wake the computer to run this task brings the machine out of sleep. On laptops the default "only if the computer is on AC power" there prevents runs on battery.

7. Or by command with schtasks

   The same works in a command prompt with administrator rights. The three schedules are alternatives, pick one of them. /sc minute /mo accepts 1 to 1439 minutes. /ru SYSTEM runs the task without a logged-in user and without a password.

   rem every 5 minutes (crontab: */5 * * * *)
   schtasks /create /tn "Export" /tr "C:\php\php.exe C:\scripts\export.php" /sc minute /mo 5 /ru SYSTEM
   
   rem daily at 6 am (crontab: 0 6 * * *)
   schtasks /create /tn "Export" /tr "C:\php\php.exe C:\scripts\export.php" /sc daily /st 06:00 /ru SYSTEM
   
   rem Monday to Friday at 6 am (crontab: 0 6 * * 1-5)
   schtasks /create /tn "Export" /tr "C:\php\php.exe C:\scripts\export.php" /sc weekly /d MON,TUE,WED,THU,FRI /st 06:00 /ru SYSTEM
   
   rem start once now, show status, delete
   schtasks /run /tn "Export"
   schtasks /query /tn "Export" /v /fo list
   schtasks /delete /tn "Export" /f

8. Without a Windows machine: create a cron job at Cronjob.de

   If your task can be reached through an address, create a free account at Cronjob.de and enter the address with the schedule you want. Click the interval or describe it in one sentence, such as "weekdays at 6 am". There is no program, no arguments and no power settings to deal with, and the machine may be switched off.

   */5 * * * *

   You can enter this expression at Cronjob.de exactly as it is – the schedule field understands crontab notation. But you do not have to know it: simply click the schedule together instead.

What the five fields of an expression like */5 * * * * mean is explained in the crontab reference – with examples and the most common pitfalls. You can build the expression in the crontab generator. Whether you need an outside service at all is shown in the comparison of the three ways.

Verification

Is it actually running?

In Task Scheduler the "Last Run Result" column shows the return value: 0x0 means success, anything else is an error. Switch on the history on the right with "Enable All Tasks History". When Cronjob.de makes the call, you see every call with status and runtime in the log instead, and from the Plus plan can get an email when one fails.

FAQ

Common questions about Windows

Is there a cron job on Windows?

Not under that name. Its counterpart is Task Scheduler, on the command line schtasks. It starts programs and scripts on a schedule, but writes the schedule as a trigger with a repetition instead of a crontab expression.

How do I translate a crontab expression for Windows?

*/5 * * * * becomes /sc minute /mo 5, 0 * * * * becomes /sc hourly, 0 6 * * * becomes /sc daily /st 06:00 and 0 6 * * 1-5 becomes /sc weekly /d MON,TUE,WED,THU,FRI /st 06:00. What an expression means exactly is shown by the crontab generator.

Does the task run when I am logged off or the PC is asleep?

Logged off yes, if it runs "whether user is logged on or not" or as SYSTEM. It only wakes the machine from sleep with the condition "Wake the computer to run this task". If the machine is fully off, the run is lost and made up at the next start with "run task as soon as possible after a scheduled start is missed".

Can I not just use cron in WSL?

Yes, the Windows Subsystem for Linux has cron. But it only runs while the Linux distribution is running. According to Microsoft, WSL shuts down an idle distribution after a timeout (setting instanceIdleTimeout, default 15 seconds). Without systemd cron does not start by itself either; that needs systemd=true in the [boot] section of /etc/wsl.conf. For tasks that have to run reliably, Task Scheduler is the safer way.

When is an online cron job better than Task Scheduler?

When the task is an address and the machine does not run around the clock. Typical are shop exports, WordPress, newsletters or scripts on web space. For tasks that work on files on exactly this machine, Task Scheduler remains the right choice.