Calculating Sale in period of time

[Magda]

Hi Everyone ! 
I am new in power bi community, just started my journey with Power BI and DAX. 

Maybe some of you came across a problem that I have. What I need:

I want to show TotalSale per Day in a period of time. My DateStart would be MIN(Date) when Sale > 3. My Max(Date) is Date chosen on a Slicer. 
To sum up: when TotalSale for the first time is > 3 I woul like to start calculating and end in chosen by slicer date. 
I have to show it on Card by OkViz with trend line to show how it had changed through time.

I have created such measure, but for some reason it's not calculating properly MIN(DATE). 

SALES_PERIOD = 
var DateStart = CALCULATE(MIN('SALES'[DateID]) ;all('DimDate'); FILTER('SALES'; 'SALES'[Sale] >3))
var DateEnd   = max('DimDate'[DateID])

return CALCULATE(
'SALES'Sale;
all(' DimDate'); 'SALES'[DateID] <= DateStart ; 'SALES'[DimDateID] >= DateEnd)

[Greg_Deckler]

Please see this post regarding How to Get Your Question Answered Quickly: https://community.powerbi.com/t5/Community-Blog/How-to-Get-Your-Question-Answered-Quickly/ba-p/38490