C# - Duration between two DateTimes in minutes

Question

I need to determine duration between two DateTimes in minutes.

However, there is a slight twist:

• exclude weekends
• only count minutes which a

Answer 1

I'm sure there's something I missed.

  TimeSpan CalcBusinessTime(DateTime a, DateTime b)
  {
     if (a > b)
     {
        DateTime tmp = a;
        a = b;
        b = tmp;
     }

     if (a.TimeOfDay < new TimeSpan(7, 0, 0))
        a = new DateTime(a.Year, a.Month, a.Day, 7, 0, 0);
     if (b.TimeOfDay > new TimeSpan(19, 0, 0))
        b = new DateTime(b.Year, b.Month, b.Day, 19, 0, 0);

     TimeSpan sum = new TimeSpan();
     TimeSpan fullDay = new TimeSpan(12, 0, 0);
     while (a < b)
     {
        if (a.DayOfWeek != DayOfWeek.Saturday && a.DayOfWeek != DayOfWeek.Sunday)
        {
           sum += (b - a < fullDay) ? b - a : fullDay;
        }
        a = a.AddDays(1);
     }

     return sum;
  }