The solution is to add a dedicated print button to the calendar navigation. When pressed, a popup window should open which renders a little from with the start and end date of the to be printed events. Default values are today as the start date and plus one month as the end date. Below the form a button "print" is located.
When pressing "print", the page renders the events in the configured time frame as a simple list with some print css stylings and issues the window.print() command in the browser.