Adding Days to a Date but Excluding Weekends


Given a date how can I add a number of days to it, but exclude weekends. For example, given 11/12/2008 (Wednesday) and adding five will result in 11/19/2008 (Wednesday) rather than 11/17/2008 (Monday).

I can think of a simple solution like looping through each day to add and checking to see if it is a weekend, but I'd like to see if there is something more elegant. I'd also be interested in any F# solution.

11/10/2008 9:49:39 PM

Accepted Answer

using Fluent DateTime

var dateTime = DateTime.Now.AddBusinessDays(4);
4/25/2018 8:38:49 AM

public DateTime AddBusinessDays(DateTime dt, int nDays)
    int weeks = nDays / 5;
    nDays %= 5;
    while(dt.DayOfWeek == DayOfWeek.Saturday || dt.DayOfWeek == DayOfWeek.Sunday)
        dt = dt.AddDays(1);

    while (nDays-- > 0)
        dt = dt.AddDays(1);
        if (dt.DayOfWeek == DayOfWeek.Saturday)
            dt = dt.AddDays(2);
    return dt.AddDays(weeks*7);

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