Get work days between two dates

WorkDays.cs

private double GetWorkDays(DateTime Start, DateTime End)
{
    double WorkDays = 1 + ((End - Start).TotalDays * 5 - (Start.DayOfWeek - End.DayOfWeek) * 2) / 7;

    if (End.DayOfWeek == DayOfWeek.Saturday) WorkDays--;
    if (Start.DayOfWeek == DayOfWeek.Sunday) WorkDays--;

    return WorkDays;
}