Private Sub Worksheet_Change(ByVal c As Range)
    Dim DR As Range, TR As Range
    Dim S As String, k As String, kk As Variant
    Dim m&
        If c.Row = 1 Then GoTo EM
        Set DR = Columns(3)
        Set TR = Columns(4)
        If CDbl(Right(Year(Date), 2)) + 12 < CDbl(Right(c, 2)) Then kk = -1 Else kk = 0
        S = Left(Year(Date), 2) + kk
            If c.Column = 3 Then k = "Date format is not dmmyyyy" Else: If c.Column = 4 Then k = "Time format is not hmm" Else GoTo EM
            If IsNumeric(c) Then
                If Len(c) = 6 Or Len(c) = 5 Then If Len(c) = 6 Then m = 3 Else m = 2
                If Len(c) = 4 Or Len(c) = 3 Then If Len(c) = 4 Then m = 2 Else m = 1
                If Not Intersect(c, DR) Is Nothing And Len(c) = 6 Or Len(c) = 5 Then c = DateSerial(CDbl(S & Right(c, 2)), CDbl(Mid(c, m, 2)), CDbl(Left(c, m - 1))): GoTo EM
                If Not Intersect(c, TR) Is Nothing And Len(c) = 4 Or Len(c) = 3 Then c = Format(TimeSerial(CDbl(Left(c, m)), CDbl(Right(c, 2)), 0), "h:mm")
            Else
                If IsDate(c) Then GoTo EM
                MsgBox k, vbExclamation + vbOKOnly, "ERROR"
            End If
EM:
        Set c = Nothing
End Sub

Private Sub Worksheet_Change(ByVal c As Range)
    Dim DR As Range, TR As Range
    Dim S As String, k As String, kk As Variant
    Dim m&
        If c.Row = 1 Or c.Cells.Count > 1 Then Exit Sub
        Set DR = Columns(3)
        Set TR = Columns(4)
            If c.Column = 3 Then k = "Date format is not dmmyy" Else: If c.Column = 4 Then k = "Time format is not hmm" Else Exit Sub
            If IsNumeric(c) Then
                If CDbl(Right(Year(Date), 2)) + 12 < CDbl(Right(c, 2)) Then kk = -1 Else kk = 0
                S = Left(Year(Date), 2) + kk
                If Len(c) = 6 Or Len(c) = 5 Then If Len(c) = 6 Then m = 3 Else m = 2
                If Len(c) = 4 Or Len(c) = 3 Then If Len(c) = 4 Then m = 2 Else m = 1
                If Not Intersect(c, DR) Is Nothing And Len(c) = 6 Or Len(c) = 5 Then c = DateSerial(CDbl(S & Right(c, 2)), CDbl(Mid(c, m, 2)), CDbl(Left(c, m - 1))): Exit Sub
                If Not Intersect(c, TR) Is Nothing And Len(c) = 4 Or Len(c) = 3 Then c = Format(TimeSerial(CDbl(Left(c, m)), CDbl(Right(c, 2)), 0), "h:mm")
            Else
                If IsDate(c) Then Exit Sub
                MsgBox k, vbExclamation + vbOKOnly, "ERROR"
            End If
End Sub

Private Sub Worksheet_Change(ByVal r As Range)
    Dim DR As Range, TR As Range, c As String
    Dim S As String, k As String, kk As Variant
    Dim v As Variant
    Dim m&, z&, x&
    c = Cells(r.Row, r.Column)
        Set DR = Columns(3)
        Set TR = Columns(4)
            If r.Column = 3 Then k = "Date format is not dmmyy" Else: If r.Column = 4 Then k = "Time format is not hmm" Else Exit Sub
            If IsNumeric(c) Then
                If c >= 5 Then If Right(Year(Date), 2) + 12 < CDbl(Right(c, 2)) Then kk = -1 Else kk = 0
                S = Left(Year(Date), 2) + kk
                If Len(c) = 6 Or Len(c) = 5 Then If Len(c) = 6 Then m = 3 Else m = 2
                If Len(c) = 4 Or Len(c) = 3 Then If Len(c) = 4 Then m = 2 Else m = 1
                If Not Intersect(Cells(r.Row, r.Column), DR) Is Nothing And Len(c) = 6 Or Len(c) = 5 Then v = DateSerial(CDbl(S & Right(c, 2)), CDbl(Mid(c, m, 2)), CDbl(Left(c, m - 1)))
                If Not Intersect(Cells(r.Row, r.Column), TR) Is Nothing And Len(c) = 4 Or Len(c) = 3 Then v = Format(TimeSerial(CDbl(Left(c, m)), CDbl(Right(c, 2)), 0), "h:mm")
                
                For x = r.Row To r.Row + r.Count - 1
                    Cells(x, r.Column) = v
                Next
                
                Exit Sub
            Else
                If IsDate(c) Then Exit Sub
                MsgBox k, vbExclamation + vbOKOnly, "ERROR"
            End If
End Sub

Private Sub Worksheet_Change(ByVal r As Range)
    Dim DR As Range, TR As Range, c As Range
    Dim S As String, k As String, kk As Variant
    Dim m&
    On Error GoTo erh
    Application.EnableEvents = False
    Set DR = Columns(3)
    Set TR = Columns(4)
    For Each c In r.Cells
        With c
            If .Row = 1 Then Exit Sub
            If IsNumeric(.Value2) Then
                If CDbl(Right(Year(Date), 2)) + 12 < CDbl(Right(.Value2, 2)) Then kk = -1 Else kk = 0
                S = Left(Year(Date), 2) + kk
                If Len(.Value2) = 6 Or Len(.Value2) = 5 Then If Len(.Value2) = 6 Then m = 3 Else m = 2
                If Len(.Value2) = 4 Or Len(.Value2) = 3 Then If Len(.Value2) = 4 Then m = 2 Else m = 1
                If Not Intersect(c, DR) Is Nothing And Len(.Value2) = 6 Or Len(.Value2) = 5 Then .Value = DateSerial(CDbl(S & Right(.Value2, 2)), CDbl(Mid(.Value2, m, 2)), CDbl(Left(.Value2, m - 1)))
                If Not Intersect(c, TR) Is Nothing And Len(.Value2) = 4 Or Len(.Value2) = 3 Then .Value = Format(TimeSerial(CDbl(Left(.Value2, m)), CDbl(Right(.Value2, 2)), 0), "h:mm")
            End If
        End With
    Next
erh:
    Application.EnableEvents = True
End Sub