Do not include weekends in date time

I just want to know on how to compute DateTime without including weekends (currently making a library system). The library is not open during weekends that is why i need to calculate the date that will not include weekends. Ex. 03/13/15 = friday and im borrowing it for 5 days. So, the return date should be in 03/20/15= friday( because i didnt include the weekends) Can you please tell me or give me some ideas? Thanks!

EDIT: ( The program suddenly freezes when i type a number)

int days = 0;
DateTime deyt = DateTime.Now;
rd.Text = deyt.ToString("MM/dd/yy");
DateTime dt = deyt.AddDays(int.Parse(textBox3.Text));


DateTime span = deyt;
while (span < dt.AddDays(1))
{
    if (span.DayOfWeek != DayOfWeek.Saturday && span.DayOfWeek != DayOfWeek.Sunday)
    {
        days++;
        span = span.AddDays(1);
        bd.Text = days.ToString("MM/dd/yy");
    }
}
Jon Skeet
people
quotationmark

There are far more efficient ways of doing this for large numbers of days, but if your code is only ever going to deal with small values, you can just use:

static DateTime AddDaysExcludingWeekends(DateTime start, int days)
{
    // Do you need this?
    if (days < 0)
    {
        throw new ArgumentException("Not implemented yet...");
    }
    DateTime current = start;
    for (int i = 0; i < days; days++)
    {
        current = current.AddDays(1);
        if (current.DayOfWeek == DayOfWeek.Sunday ||
            current.DayOfWeek == DayOfWeek.Saturday)
        {
            // Effectively force "go round again" behaviour.
            i--;
        }
    }
    return current;
}

Or an alternative approach:

static DateTime AddDaysExcludingWeekends(DateTime start, int days)
{
    // Do you need this?
    if (days < 0)
    {
        throw new ArgumentException("Not implemented yet...");
    }
    DateTime current = start;
    for (int i = 0; i < days; days++)
    {
        // Loop at least once, and keep going until we're on
        // a weekday.
        do
        {
           current = current.AddDays(1);
        }
        while (current.DayOfWeek == DayOfWeek.Sunday ||
               current.DayOfWeek == DayOfWeek.Saturday);
    }
    return current;
}

Note that if you pass in days=0, that will return the original date even if it is on a weekend. It's not clear whether or not you want that behaviour, or whether it should skip to the Monday.

people

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