Week Number is INCORRECT

Hey Guys,

Good day. I would like to ask for some help, because I would like to create a column for WEEK Number for each dates, but I am getting incorrect values, e.g : March 26, 2017 to March 31, 2017, I am expecting to get WEEK 5 for those dates, but I am getting WEEK 1 which INCORRECT.

DayCount = Duration.Days(Duration.From(EndDate - StartDate)),
Source = List.Dates(StartDate,DayCount,#duration(1,0,0,0)),
TableFromList = Table.FromList(Source, Splitter.SplitByNothing()),
ChangedType = Table.TransformColumnTypes(TableFromList,{{"Column1", type date}}),
RenamedColumns = Table.RenameColumns(ChangedType,{{"Column1", "Date"}}),
InsertYear = Table.AddColumn(RenamedColumns, "Year", each Date.Year([Date])),
InsertQuarter = Table.AddColumn(InsertYear, "QuarterOfYear", each Date.QuarterOfYear([Date])),
InsertMonth = Table.AddColumn(InsertQuarter, "MonthOfYear", each Date.Month([Date])),
InsertDay = Table.AddColumn(InsertMonth, "DayOfMonth", each Date.Day([Date])),
InsertDayInt = Table.AddColumn(InsertDay, "DateInt", each [Year] * 10000 + [MonthOfYear] * 100 + [DayOfMonth]),
InsertMonthName = Table.AddColumn(InsertDayInt, "MonthName", each Date.ToText([Date], "MMMM", Culture), type text),
InsertCalendarMonth = Table.AddColumn(InsertMonthName, "MonthInCalendar", each (try(Text.Range([MonthName],0,3)) otherwise [MonthName]) & " " & Number.ToText([Year])),
InsertYearMonth = Table.AddColumn(InsertCalendarMonth, "YearMonthCalendar", each [Year] * 100 + [MonthOfYear]),
InsertCalendarQtr = Table.AddColumn(InsertYearMonth, "QuarterInCalendar", each "Q" & Number.ToText([QuarterOfYear]) & " " & Number.ToText([Year])),
InsertDayWeek = Table.AddColumn(InsertCalendarQtr, "DayInWeek", each Date.DayOfWeek([Date])),
InsertDayName = Table.AddColumn(InsertDayWeek, "DayOfWeekName", each Date.ToText([Date], "dddd", Culture), type text),
InsertWeekEnding = Table.AddColumn(InsertDayName, "WeekEnding", each Date.EndOfWeek([Date]), type date)

Source = Query1(#date(2017, 1, 1), #date(2017, 12, 31), null),
#"Inserted Week of Month" = Table.AddColumn(Source, "WeekOfMonth", each Date.WeekOfMonth([WeekEnding]), type number),
#"Added Custom" = Table.AddColumn(#"Inserted Week of Month", "WeekNameMonth", each if [WeekOfMonth] = 1 then "Week 1"
else if [WeekOfMonth] = 2 then "Week 2"
else if [WeekOfMonth] = 3 then "Week 3"
else "Week 4"),
#"Renamed Columns" = Table.RenameColumns(#"Added Custom",{{"WeekNameMonth", "Weeks"}, {"DayOfWeekName", "Day of the Week"}})

SEE attached screenshot

THANK YOU SO MUCH!

In the Query Editor-The week number for the first week of the year is not accurate. I am using the date.weekofyear (by copying the transaction date column and transforming it into the week of the date). 

Here is what I'm seeing: (Sorry i cant figure out to attach a picture)

Transaction Date    Week of Year of Date   Start of Week   End of Week

12/29/2017            52                                  12/24/2017     12/30/2017

12/30/2017            52                                   12/24/2017     12/30/2017

12/31/2017            53                                    12/31/17         1/6/18

1/1/2018                 1                                     12/31/17         1/6/18

1/2/2018                1                                       12/31/17         1/6/18

As you can see, all of the tranasctions are marked with the correct week# EXCEPT the transactions on 12/31/17. It is putting them in week 53, and that is the only date in week 53. The start and end of week columns are being calculated correctly, but it is pulling the wrong week number. 

hi,

just sharing of what works for me on this leap year (total wk 53 ) i found somewhere on the net last time :

WW =
VAR wk = WEEKNUM('Calendar Relative'[Date], 2)
VAR yr = YEAR('Calendar Relative'[Date])
VAR isowk = WEEKNUM('Calendar Relative'[Date], 21)
return
IF (wk > 50 && isowk < 5, FORMAT(isowk,"00") & " " & yr+1,
IF (wk < 5 && isowk >50 , FORMAT(isowk,"00") & " " & yr-1, FORMAT(isowk,"00") & " " & yr))