Calculate a value from a schedule for a specifi week

Hi Oleander ,

Please add the following custom function to convert the date to ISO week number. 

Referencing: M functions to convert between ISO 8601 Week  

let
    getISO8601Week = (someDate as date) =>
        let
            getDayOfWeek = (d as date) =>
                let
                    result = 1 + Date.DayOfWeek(d, Day.Monday)
                in
                    result,

            getNaiveWeek = (inDate as date) =>
                let
                    // monday = 1, sunday = 7
                    weekday = getDayOfWeek(inDate),

                    weekdayOfJan4th = getDayOfWeek(#date(Date.Year(inDate), 1, 4)),

                    ordinal = Date.DayOfYear(inDate),

                    naiveWeek = Number.RoundDown(
                        (ordinal - weekday + 10) / 7
                    )
                in
                    naiveWeek,

            thisYear = Date.Year(someDate),

            priorYear = thisYear - 1,

            nwn = getNaiveWeek(someDate),

            lastWeekOfPriorYear =
                getNaiveWeek(#date(priorYear, 12, 28)),

            // http://stackoverflow.com/a/34092382/2014893
            lastWeekOfThisYear =
                getNaiveWeek(#date(thisYear, 12, 28)),

            weekNumber =
                if
                    nwn < 1
                then
                    lastWeekOfPriorYear
                else
                    if
                        nwn > lastWeekOfThisYear
                    then
                        1
                    else
                        nwn 
        in
            weekNumber
in
    getISO8601Week

Then modify the formula of the custom column.

WeekList = {DateToISOWeek([Start date])..DateToISOWeek([End date])}

Best Regards,
Winniz

Hi,

This works though all dates must be in the same year.

//Göran