Function to Add Business days - C#

Introduction

      In many cases developers have a demand of calculation and manipulations with business dates.

Scenario:

      We want to add “N” business days/working days to a current date (Or from a specified date). Where “N” is the number of business days.

Solution:

      In this blog I have described how to add “N” business days/working days to a date

The below C# function does it all for you. Simply pass in a date, along with the number of working days you want to add.

public DateTime AddBusinessDays(DateTime DateIn, int Days2Add)
{
    DateTime resultDate;
    // Adds the N (Days2Add) working days to DateIn (Today)
    resultDate = DateIn.AddDays(Days2Add);
         
    // Loops and adds only non-weekend day(working days)
    while (resultDate.DayOfWeek == DayOfWeek.Saturday || resultDate.DayOfWeek == DayOfWeek.Sunday)
    {
        resultDate = resultDate.AddDays((Days2Add < 0 ? -1 : 1));
    }
    return resultDate;
}

And here's how you call it in your application:

private void button1_Click(object sender, EventArgs e)
{
    DateTime newDate = AddBusinessDays(DateTime.Today, 6);
    MessageBox.Show("The 6th Business day from today is {0}", newDate.ToString());
}

The above code is Tested