Marius van Witzenburg We fight for our survival, we fight!

How to add week numbers to iCal on Mac OS X

To make Mac OS X show week numbers in iCal is actually not that difficult.
You simply need to add the week number to the full date notation and your done.

Goto the System preferences

Path:  » System Preferences...

Goto Language & Text

Path:  » System Preferences... » Language & Text

Goto the tab Formats and then click Customize...

Path:  » System Preferences... » Language & Text » Formats

You will see a window where you can modify your notation format for date and time.
Now you have to put the week number of the year in the right place. Follow the red arrows

Drag the week number to the full date field

Path:  » System Preferences... » Language & Text » Formats » Customize...

Finally close all windows and check the clock on the top right.

Now start your iCal and check the date bar at the top.

As you see, its really simple to get this done

NOTE: Offset in the week number
Be sure you have the right country selected for your formats. Else you might end up with a week number with an offset. In my case the week number would be one week ahead. This cause my main country is The Netherlands and I have my system on United Kingdom. The thing you have to do is first select Dutch -> Nederlands and then change the week number. It might show weird having Dutch day names in iCal but hey... Apple made it work like this out of the box

Update 26-07-2011:
This works only for iCal versions below 5.0 which runs on 10.7 Lion, due the iPad layout the week numbers are not possible in this way!

As a temporarily solution subscribe to one of these (open page, click subscribe button):

• For European: http://icalshare.com/calendars/195
• For Norwegian: http://icalshare.com/calendars/190