Referencing a date range to calculate a column value

Here is your DateRange table:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45WMlTSUTIAYgUgNrLQdSxN1zW0VIrViVYyAomgiAJVGuo6FhTpGhmAVRiDZPVMTFEkQEbFxgIA", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [ID = _t, Value = _t, StartDate = _t, EndDate = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Value", type number}, {"StartDate", type date}, {"EndDate", type date}})
in
    #"Changed Type"

Load this into Power BI. Then in DAX create a Calendar table (or use your existing one)

Dates = CALENDAR(DATE(2019,6,1),DATE(2020,6,1))

And finally add the calculated column for the factor to the Dates table:

Factor = 
var a = ADDCOLUMNS(DateRange
        ,"GTS",if(ISBLANK(DateRange[StartDate]) || [Date]>=DateRange[StartDate],1,0)
        ,"LTE",if(ISBLANK(DateRange[EndDate]) || [Date]<DateRange[EndDate],1,0))
return SUMX(a,[Value]*[GTS]*[LTE])