C# - Anzahl der Wochentage zwischen zwei Daten ermitteln

private int CountWeekdays(DateTime startTime, DateTime endTime)
{
    TimeSpan timeSpan = endTime - startTime;
    DateTime dateTime;
    int weekdays = 0;
    for (int i = 0; i < timeSpan.Days; i++)
    {
        dateTime = startTime.AddDays(i);
        if (IsWeekDay(dateTime))
            weekdays++;
    }
    return weekdays;
}

private bool IsWeekDay(DateTime dateTime)
{
    return ((dateTime.DayOfWeek != DayOfWeek.Saturday) && (dateTime.DayOfWeek != DayOfWeek.Sunday)
}