How to check for equal values in cells with a for loop?

Question

I want to check if the text value in a cell is the same as in the cell below with a for loop.

If the value in Cell(1) and Cell(2) does not match I want the value from Cell(3) written in Cell(4).

I get an error

"Overflow (Error 6)"

Dim i As Integer

For i = 1 To Rows.Count

    If Cells(2 + i,21) = Cells(3 + i,21) Then
        i = i + 1
    Else
        a = Cells(3 + i, 1)
        j = j + 1
        Cells(228 + j, 3) = a
    End If

Next i

End Sub

I have a production output and a timeline from 6 am to 12 am and I want to create a timetable as seen below.

Screenshot:

Answer 1

You could use

Option Explicit

Sub test()

    Dim LastRowA As Long, i As Long, j As Long, LastRowW As Long
    Dim StartTime As Date, EndTime As Date, strOutPut

    j = 0

    With ThisWorkbook.Worksheets("Sheet1")

        LastRowA = .Cells(.Rows.Count, "A").End(xlUp).Row

        For i = 3 To LastRowA

            If i > j - 1 Then

                StartTime = .Range("A" & i).Value
                strOutPut = .Range("U" & i).Value

                For j = i + 1 To LastRowA + 1

                    If strOutPut <> .Range("U" & j).Value Then

                        EndTime = .Range("A" & j - 1).Value
                        LastRow = .Cells(.Rows.Count, "W").End(xlUp).Row

                        .Range("W" & LastRow + 1).Value = StartTime
                        .Range("X" & LastRow + 1).Value = EndTime
                        .Range("Y" & LastRow + 1).Value = strOutPut

                        Exit For

                    End If

                Next j

            End If

        Next i

    End With

End Sub

Result