Thanks to Tiernan to point me in the right direction for creating VCalendar links. However (as usual with dates format) I have some issues with the Date format as you can see below.
I tried everything but Outlook seems to accept only this format. Of course it works but as you can see if you don't deploy the mini calendar view, you can wrongly think the event will be saved for the 7th of January and not the 1st of July.
Any ideas ?

UPDATE: Problem solved (check the comment), thanks to Brian