Open Source Document Management System | OpenKM

Hello,
is it possible:
If an user logs into the openkm-ce, he should get a reminder or see something like a task/todo every 14 days to clean the window (or do something else). How to do this, the user should see a link to a "how to clean a window"-document.

Is this in openkm possible or have I to use something else like a calender-app?

Thanks for help!

In the administration there's the option to send messages to the users. I suggest check it manually. Another option could be send and email address. You could automate both options from with a cron job.