Only admin profiles can do it. The configuration will be applied for all the users.
Click on your initials, then on "Configure":
Click on the tab" Configuration" and go to the paragraph "calendar configuration".
These parameters will be applied for all the new databases created. If you want to change it after, for a database, you can follow the procedure, point 8 :
How to change the parameters of a base?
Don't forget to click on "Save", at the bottom right of the screen.