Calculate the number of business days between two dates?

Question

In C#, how can I calculate the number of business (or weekdays) days between two dates?

Answer 1

Yet another approach for calculating business days, not considering holidays, but taking into account the time of day returning a fractional amount of days:

public static double GetBusinessDays(DateTime startD, DateTime endD)
{
    while (IsWeekend(startD))
        startD = startD.Date.AddDays(1);

    while (IsWeekend(endD))
        endD = endD.Date.AddDays(-1);

    var bussDays = (endD - startD).TotalDays -
        (2 * ((int)(endD - startD).TotalDays / 7)) -
        (startD.DayOfWeek > endD.DayOfWeek ? 2 : 0);

    return bussDays;
}

public static bool IsWeekend(DateTime d)
{
    return d.DayOfWeek == DayOfWeek.Saturday || d.DayOfWeek == DayOfWeek.Sunday;
}

You can fiddle with it here: https://rextester.com/ASHRS53997