Weeknum

Was given following formula which worked fine until the year changed -
=WEEKNUM(A2)-WEEKNUM(DATE(2005,3,1))+1

My spreadsheet runs timestamps from 1 mar 2005 thru to 1 mar 2007. 1 Mar 2005 was week 1 and worked great thru to 31 dec 2005 which was week 44.
As soon as the date changed to 1 Jan 2006 - formula returned - 8 !!!!
I have tried fiddling around but still have no success in January 2006 carrying on from 2005 increasing from 44 onwards.
Spreadsheet shows

Date (A2 etc) ........ Week number
01/03/2005 ...................1
thru to
31/12/2005 ...................44

then !
01/01/2006 .................. -8

Would appreciate any help again - thanks in advance
Chaz

Yes, got that now !! Works fine - thanks a lot for your assistance.

Excellent forum - great guys and gals helping out.