時間帯ごとに時間を分割するプログラム

Function getFunAsa(start_time As Date, end_time As Date) As Integer
    Dim A As Integer
    Dim B As Integer
    Dim start_time_1 As Date
    Dim end_time_1 As Date
    Dim start_time_2 As Date
    Dim end_time_2 As Date
    
    start_time_1 = #1/1/2023 4:00:00 AM#
    end_time_1 = #1/1/2023 6:00:00 AM#
    start_time_2 = #1/2/2023 4:00:00 AM#
    end_time_2 = #1/2/2023 6:00:00 AM#
    
    If start_time <= end_time_1 And end_time >= start_time_1 Then
        A = DateDiff("n", IIf(start_time < start_time_1, start_time_1, start_time), IIf(end_time > end_time_1, end_time_1, end_time))
        Debug.Print "1/1 4:00～1/1 06:00までの時間帯の分数: " & A
    End If
    
    If start_time <= end_time_2 And end_time >= start_time_2 Then
        B = DateDiff("n", IIf(start_time < start_time_2, start_time_2, start_time), IIf(end_time > end_time_2, end_time_2, end_time))
        Debug.Print "1/2 4:00～1/2 06:00までの時間帯の分数: " & B
    End If
    
    getFunAsa = A + B
End Function