From ModMyi - Wiki

This tut will teach you how to get weeknumbers on your iphone calender and how to sync your Google Calender with the one you have on your iPhone.

Since i got the iphone in my hands i discovered a little missing feature which would have made my life easier. Have you experienced someone said that u had a task for wednesday in week 45. WEEK 45 ? wtf... Well if u had week numbers on your iphone you could find week 45 in matter of seconds...

Tut: So the first thing you will have to do, is making a Google Calender account (totally free): http://www.google.com/calendar

Remember to set the timezone to the same as your iphone calender.

Once you have set up your google calender you should go to: http://recover89.googlepages.com/googlecalendarweeknumbers

And click on add it (my weeks start on Sun/Mon-days) in the upper right corner. And then select "Yes, add this calender". Now you will see the weeknumber appear just beneath Sunday or Monday, depends on what u selected.

Now for setting up the iPhone!

-Goto Cydia and Install - NemusSync. -Now go back to the springboard and go into NemusSync. -In NemusSync flick all settings on, and finally add your Google Calender account. -And at last go into "standard calender" in NemusSync and select the Calender which isn't "week numbers". - PRESS [SYNC CALENDER] - AND VOILA! Now you have week numbers in your iPhone calender and you also have every little detail from your iphone and google calender available on both. They are totally sync'ed!

All Credits goes to the creator of NemusSync - Sangwook Han, without this app we wouldn't be able to do this!

tut by: Turanli