Compare columns containing dates

Dim r As Range, c As Range, m As Integer 
Dim j As Integer, k As Integer, ddate(1 To 25) 
Dim rb As Range, cfind As Range, runique As Range 
Dim lastcell As Range 
Sub test() 
m = Range("a1").End(xlDown).Row + 5 

j = 1 
Set r = Range(Range("a2"), Range("a2").End(xlDown).End(xlToRight)) 
For k = 1 To 5 
Set rb = Range("B2:B6").Offset(, (k - 1) * 2) 
'MsgBox rb.Address 

For Each c In rb 
If WorksheetFunction.CountIf(r, c.Value) = 5 Then 
ddate(j) = c.Value 
'MsgBox ddate(j) 

Range("a" & m).Offset(j - 1, 0) = ddate(j) 
j = j + 1 
End If 
Next c 
Next k 
Range("A" & m - 1) = "common dates" 
Set runique = Range(Cells(m - 1, "A"), Cells(Rows.Count, "A").End(xlUp)) 
runique.AdvancedFilter Action:=xlFilterCopy, copytorange:=Cells(Rows.Count, "A").End(xlUp).Offset(5, 0), unique:=True 
Set lastcell = Cells(Rows.Count, "A").End(xlUp) 
Set runique = Range(lastcell, lastcell.End(xlUp).Offset(1, 0)) 
'MsgBox runique.Address 
For Each c In runique 
For k = 1 To 5 
Set rb = Range("B2:B6").Offset(, (k - 1) * 2) 
'MsgBox rb.Address 
Set cfind = rb.Cells.Find(what:=c.Value, lookat:=xlWhole) 
Cells(c.Row, Columns.Count).End(xlToLeft).Offset(0, 1) = Cells(cfind.Row, "A") 
Cells(c.Row, Columns.Count).End(xlToLeft).Offset(0, 1) = Cells(cfind.Row, cfind.Column + 1) 
Next k 
Next c 
Range(Cells(m - 1, "A"), Cells(m - 1, "A").End(xlDown)).EntireRow.Delete 
End Sub 

Sub undo() 
m = Range("a1").End(xlDown).Row 
Set r = Range(Cells(m + 1, "A"), Cells(Rows.Count, "A").End(xlUp)) 
'MsgBox r.Address 
r.EntireRow.Delete 
End Sub