Group by Week
You probably noticed that Excel allows you to group by day, month, quarter, and year. There is no standard grouping for week. You can, however, define a group that bunches up groups of seven days.
By default Excel starts the week based on the first date found in the data. This means that the default week would run from Tuesday January 1, 2006 through Monday December 31, 2007. You can override this by changing the Start parameter from true to an actual date. Use the WeekDay function to determine how many days to adjust the start date.
There is one limitation to grouping by week. When you group by week, you cannot also group by any other measure. It is not valid to group by week and quarter.
Listing 5 creates the report shown in Figure 17.
Listing 5. The Code Used to Group by Week Must Figure Out the Monday Nearest the Start ofYour Data
Sub ReportByWeek()
Dim WSD As Worksheet
Dim PTCache As PivotCache
Dim PT As PivotTable
Dim PRange As Range
Dim FinalRow As Long
Set WSD = Worksheets("PivotTable")
Dim WSR As Worksheet
' Delete any prior pivot tables
For Each PT In WSD.PivotTables
PT.TableRange2.Clear
Next PT
' Define input area and set up a Pivot Cache
FinalRow = WSD.Cells(Application.Rows.Count, 1).End(xlUp).Row
FinalCol = WSD.Cells(1, Application.Columns.Count). _
End(xlToLeft).Column
Set PRange = WSD.Cells(1, 1).Resize(FinalRow, FinalCol)
Set PTCache = ActiveWorkbook.PivotCaches.Add(SourceType:= _
xlDatabase, SourceData:=PRange.Address)
' Create the Pivot Table from the Pivot Cache
Set PT = PTCache.CreatePivotTable(TableDestination:=WSD. _
Cells(2, FinalCol + 2), TableName:="PivotTable1")
' Turn off updating while building the table
PT.ManualUpdate = True
' Set up the row fields
PT.AddFields RowFields:="In Balance Date", ColumnFields:="Region"
' Set up the data fields
With PT.PivotFields("Revenue")
.Orientation = xlDataField
.Function = xlSum
.Position = 1
.NumberFormat = "#,##0"
End With
' Ensure that you get zeroes instead of blanks in the data area
PT.NullString = "0"
' Calc the pivot table to allow the date label to be drawn
PT.ManualUpdate = False
PT.ManualUpdate = True
' Group Date by Week.
'Figure out the first Monday before the minimum date
FirstDate = PT.PivotFields("In Balance Date").LabelRange. _
Offset(1, 0).Value
WhichDay = Weekday(FirstDate, 3)
StartDate = FirstDate - WhichDay
PT.PivotFields("In Balance Date").LabelRange.Group _
Start:=StartDate, End:=True, By:=7, _
Periods:=Array(False, False, False, True, False, False, False)
' Calc the pivot table
PT.ManualUpdate = False
PT.ManualUpdate = True
End Sub
17. Use the Number of Days setting to group by week.
