Add "week number" option to Ubuntu calendar

Here in Denmark, and in Scandinavia I think, we use week numbers. This is simply that the 52 weeks of the year are notated.

For example, when we plan vacation, we say: I will have my vacation at week 31 and 32. This means from monday july 29th to sunday the 11th. By the way, we also have the start of the week on mondays.

Here is a random example I've found:
http://cdn.vertex42.com/calendars/images/yearly-calendar-week-numbers.png

It would be very appreciated, if this feature would be added as an option.

Best regards
Peter Steffensen