weekly calculation for year to date starting first sunday

[ksairam81]

Hello

I am unable to find a solution for a meaure which need to show weekly calculation year to date starting first sunday on the graph.
For clear understanding as of now we are sitting on todays date , so if we take same time last year to till date and it should be starting with first sunday .
I can get calculated for current year my logic works fine but if i try to do it for year to date my values are not showing correct on the graph

i created start date query item -- _add_years(current_date,-1)
then Day of week --- _day_of_week([StartDate],8)

to get First Sunday --- case when [Day Of Week] = 1
then _add_days([StartDate], 6)
when [Day Of Week] = 2
then _add_days([StartDate],5)
when [Day Of Week] = 3
then _add_days([StartDate],4)
when [Day Of Week] = 4
then _add_days([StartDate],3)
when [Day Of Week] = 5
then _add_days([StartDate],2)
when [Day Of Week] = 6
then _add_days([StartDate],1)
when [Day Of Week] = 7
then [StartDate]
else [StartDate]
end


then date to display on graph --- _add_days([First Sunday],([Common].[dim_date].[cal_week_in_year]-1)*7)

and my filter is calendar date between start date and current date


also as i said for current year it works fine and my logic just need to change Start date --- _add_years(_add_days(current_date,-1*(_day_of_year(current_date)-1)),0)

can anybody plz help me out for the solution