YTD DAX

Anonymous , Try measure like this using time intelligence

YTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESYTD('Date'[Date],"12/31"))
Last YTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESYTD(dateadd('Date'[Date],-1,Year),"12/31"))

or

YTD QTY forced=
var _max = eomonth(today(),-1)
return
if(max('Date'[Date])<=_max, calculate(Sum('order'[Qty]),DATESYTD('Date'[Date])), blank())
//or
//calculate(Sum('order'[Qty]),DATESYTD('Date'[Date]),filter('Date','Date'[Date]<=_max))
//calculate(TOTALYTD(Sum('order'[Qty]),'Date'[Date]),filter('Date','Date'[Date]<=_max))

LYTD QTY forced=

var _today = eomonth(today(),-1)
var _max = date(year(_today )-1,month(_today ),day(_today ))
return
if(max('Date'[Date])<=_max, CALCULATE(Sum('order'[Qty]),DATESYTD(dateadd('Date'[Date],-1,year)),'Date'[Date]<=_max), blank())
//OR
//CALCULATE(Sum('order'[Qty]),DATESYTD(dateadd('Date'[Date],-1,year)),'Date'[Date]<=_max)
//TOTALYTD(Sum('order'[Qty]),dateadd('Date'[Date],-1,year),'Date'[Date]<=_max)