So I’ve been using owncloud as my main calendar (together with syncing to my phone and tablet). Sometimes it can be useful to have weeknumbers show up in your calendar. I didn’t know the calendar in owncloud was based on the the Fullcalendar project. Digging around a bit on the website shows there is a setting to enable the weeknumber in the calendar!

Looking in the owncloud directory the file is quickly found. Open up the file (relative to your owncloud installation)

There is a line that has the following default value:

Change it to

and you’re set! Weeknumbers now show up in the upper left part of the calendar.