Thread: Unable to Match property of Worksheet class function

Hi in below stated code i do get this error:
Unable to Match property of Worksheet class function.
It seems I made everything right, but I cannot figure out why this message appears. Hope you can find out the problem...

Code:

Private Sub StudentButton_Click()
    Dim DateField As Range, ResultTable As Range
    Dim StartDay As Date, EndDay As Date
    Dim lRow As Long, lColumn As Long
    Dim sDayPos As Long, eDayPos As Long
    Dim StartRow As Integer, StartColumn As Integer
    Dim MyMonth As Integer, MyYears As Integer, lDate As Integer

    StartRow = Range("FirstCell").Row
    StartColumn = Range("FirstCell").Column

    Set ResultTable = Range("ResultTable")
    Set DateField = Sheets(2).Range("Dates")
    
    'Getting Last column number
    With Range(StartRow & ":" & StartRow)
         lColumn = .Cells(1, .Columns.Count).End(xlToLeft).Column
    End With

    For MyYears = 1 To lColumn - StartColumn
        For MyMonth = 1 To 12

----------------------------------------- SOME PART OF CODE BETWEEN ------------------------------

            'Getting positions for Fist day and last day of a month in Datafield Range
            With WorksheetFunction
                sDayPos = .Match(StartDay, DateField, 0)   <<<<<<< CAUSES ERROR
                eDayPos = .Match(EndDay, DateField, 0)    <<<<<<< CAUSES ERROR
            End With

        MsgBox sDayPos & " and " & eDayPos
        Next MyMonth
    Next MyYears
End Sub