how to sum a value based on two dates

Hi everone, I'm struggling with a measure that requires a sum of a value only if the Date1 is minor than Date2 or Data2 = null.

I tried first, 

Measure = 

VAR D1 = LASTDATE('Table'[Date1])

RETURN

CALCULATE(SUM('Table'[Value]),Table[Date2] >  D1 || Table[Date2] = BLANK())

not sure if the filter of calculate will respect the followed condition