Considering Specific Days Between Two Dates

Hi Ryukatan10 

can you share sample data if the 2nd table?

Hi tamerj1  the second table is like this:

I have the dates and a number that identifies the Weekday Name, 1 for Monday and 7 for Sunday

// All you need is a middleman table
// that you'll then join to both
// the Flights table and the one with
// dates. It'll be a helper, so it's
// best to hide it in the UI as it
// should only be used by measures.
// It's best to do such things in Power
// Query but if your data is not too
// large, then you can also do it via
// DAX. The Flights table should also
// be restructured so that the days
// are not columns but values in a column.
// The dataset you have right now is not
// in optimal format for PBI consumption.
// However, if you insist on this format,
// here's the code:
FlightDateMiddleman = // new table
selectcolumns(
    generate(
        Flights,
        var dateStart = Flights[Begin Operation]
        var dateEnd = Flights[End Operation]
        // because of the format of your table,
        // you have to do such ugly stunts...
        var dayStepSize = 
            maxx(
                {   Flights[Mon],
                    Flights[Tue],
                    Flights[Wed],
                    Flights[Thu],
                    Flights[Fri],
                    Flights[Sat],
                    Flights[Sun]
                },
                [Value]
            )
        var dates = 
            SELECTCOLUMNS(
                GENERATESERIES( dateStart, dateEnd, dayStepSize ),
                "@Date", [Value]
            )
        return
            dates
    ),
    "Flight", Flights[Flight],
    "Date", [@Date]
)

method 1, in PQ editor, only bases on the table of Flights

NewStep= #table({"Flight","Date"},List.TransformMany(Table.ToRows(PreviousStepName),each List.Select(List.Dates(Date.From(_{9}),Duration.Days(_{10}-_{9})+1,#duration(1,0,0,0)),(x)=>List.Contains(List.Range(_,2,7),Date.DayOfWeek(x,Day.Monday)+1)),(x,y)=>{x{0},y}))

mehod 2, in dax with the same logic

NewTable=SELECTCOLUMNS(GENERATE(Flights,FILTER(DATESBETWEEN(DateTable[Date],Flights[Begin Operation],Flights[End Operation]), VAR _wn=WEEKDAY(DateTable[Date],2) RETURN Filghts[Mon]=_wn||Filghts[Tue]=_wn||Filghts[Wed]=_wn||Filghts[Thu]=_wn||Filghts[Fri]=_wn||Filghts[Sat]=_wn||Filghts[Sun]=_wn)),"Flight",Filghts[Flight],"Date",DateTable[Date])