c# - Determine the difference between two DateTimes, only counting opening hours

Question

For our support software in C#, I need to determine the time span between two DateTimes, but I only want opening hours counted (i.e. weekdays from 09:00 to 17:00).

So, for instance, if the first DateTime is 15/02/2011 16:00 and the second is 16/02/2011 10:00, the method shall return 2 hours.

Any help is greatly appreciated!

Answer 1

DateTime start = DateTime.Parse("15/02/2011 16:00");
DateTime end = DateTime.Parse("16/02/2011 10:00");

int count = 0;

for (var i = start; i < end; i = i.AddHours(1))
{
    if (i.DayOfWeek != DayOfWeek.Saturday && i.DayOfWeek != DayOfWeek.Sunday)
    {
        if (i.TimeOfDay.Hours >= 9 && i.TimeOfDay.Hours < 17)
        {
            count++;
        }
    }
}

Console.WriteLine(count);