Calculate what the date will be based on startdate and value using PHP skip weekends

Question

I have a startdate, let's say this is $startDate = 2012-08-01; and I have a variable that stores an INT value, lets say this is $value = 10;

I would like to calculate what the date would be from startdate + 10 days and skip weekends.

Using the above values the result would be 2012-08-15

How would this be done?

Answer 1

This is far from efficient, but who cares about that right when it is readable? :)

<?php
function calculateNextDate($startDate, $days)
{
        $dateTime = new DateTime($startDate);

        while($days) {
            $dateTime->add(new DateInterval('P1D'));    

            if ($dateTime->format('N') < 6) {
                $days--;
            }
        }

        return $dateTime->format('Y-m-d');
}

echo calculateNextDate('2012-08-01', 10); // return 2012-08-15

DEMO

What happens should be pretty easy to follow. First we create a new DateTime object using the date provided by the user. After that we are looping through the days we want to add to the date. When we hit a day in the weekend we don't subtract a day from the days we want to add to the date.