Two sets of data question

[Dazzybeeguy]

Sheet 1 Column E has a unique references i.e A123456AA and column K has a date

I have say in sheet 2 column W a corresponding list of unique references but with revised dates in column X.

I want to change the dates in Column K if a new date is for the same unique reference is in sheet 2 column X

Thanks

 

[mumps]

Try:

Sub CompareData()
    Application.ScreenUpdating = False
    Dim srcWS As Worksheet, desWS As Worksheet, v1 As Variant, v2 As Variant, dic As Object
    Set srcWS = Sheets("Sheet2")
    Set desWS = Sheets("Sheet1")
    v1 = srcWS.Range("W2", srcWS.Range("W" & Rows.Count).End(xlUp)).Resize(, 2).Value
    v2 = desWS.Range("A2", desWS.Range("A" & Rows.Count).End(xlUp)).Resize(, 11).Value
    Set dic = CreateObject("Scripting.Dictionary")
    For i = LBound(v1) To UBound(v1)
        If Not dic.exists(v1(i, 1)) Then
            dic.Add v1(i, 1), v1(i, 2)
        End If
    Next i
    For i = LBound(v2) To UBound(v2)
        If dic.exists(v2(i, 1)) Then
            desWS.Range("K" & i + 1) = dic(v2(i, 1))
        End If
    Next i
    Application.ScreenUpdating = True
End Sub