I would handle it this way

ldDate = {^2008-12-28}
...
lnWeek = WEEK(ldDate,1)
IF lnWeek = 1 AND MONTH(ldDate) = 12
	lnWeek = WEEK(ldDate-7,1) + 1
ENDIF	

? lnWeek 

>How did you get exactly the value of year 2012 I mean.. did you try all 31 days untill there or has follow any other logic?
>
>to deal with that I just see
>
>

IF  lnweek = 1 AND lnmes>11
>     lnweek			= 53
>endif

>
>sounds not smart.. but??