Hello Jan–welcome back to the forums. π
Good question. You can certainly add links manually. In other words, you can override the Month View template and add links to it as you need. See our Themer’s Guide for more details on how template overrides work.
If you want to display a link for each event, you could use the same idea but override theΒ month/tooltip.php file instead and output the Event Website field in the tooltip for the event.
This type of customization is possible, but it will be outside the level of support we can provide here in the forums. Hopefully this helps get you started and please feel free to let me know if you have specific follow-up questions here. π
Cheers!
Geoff