Dynamic last December previous year with DAX

I'm rather new with the DAX formulas and I had a bit of trouble to resolve this issue in SSAS Tabular recently. I did solve it but I am wondering if it was the right way to do it?

My customer wanted a measure that would show the outcome of their projects. The measure should show the outcome from the project start date to December 31 PREVIOUS year. And it had to be dynamic since we don't know what year last December is. The customer wanted a pivot table in Excel to show the measure.

I tried a lot of DAX-date formulas but I didn't get it to work. But eventually I ended up with the following solution: I created a hidden measure called "LastPeriodPreviousYear" and it looked like this:

 LastPeriodPreviousYear:= LASTDATE(PREVIOUSYEAR(Period[Month_Date]))

Then I created a new measure that used LastPeriodPreviousYear, and it look like this:

Outcome PTD last year:= CALCULATE ( SUM ( MOD001[Amount] ); DATESBETWEEN ( Period[Month_Date]; BLANK (); [LastPeriodPreviousYear] ) )

These two calculations gave me the result that I wanted, and the customer is satisfied. But! I am curious and I want to learn. Is there a simpler/better/more good looking way to solve this matter? Thanks in advance!