how to find the last monday of the month

Question

I\'m not sure how to go about this one. I\'m building a calendar in PHP and need users to be able to add a repeating event that follows the following rule:

Last [DOW

Answer 1

I have a generic function for you to calculate the nth day of a month. Hope this could help you to resolve your issue.

function get_Nth_dow($dow, $occurence, $m, $y)
{
    $numdays = date('t', mktime(0, 0, 0, $m, 1, $y));
    $add = 7 * ($occurence - 1);
    $firstdow = date('w', mktime(0, 0, 0, $m, 1, $y));
    $diff = $firstdow - $dow;

    $day_of_month = 1;
    if ($diff > 0)
    {
        $day_of_month += ($add - $diff);
    }
    elseif ($diff < $numdays)
    {
        $day_of_month -= ($diff - $add);
    }

    return $day_of_month;
}

$DOW = day of the week (0 = Sunday, 6 = Saturday).

$X = occurence (1 = first, 2 = third, etc..). If the given month does

not have the occurrence, then it will return the last. For example, if

you ask for the 7th occurrence of Friday, it will return the last

Friday of the month. $M = month $Y = year

Example, get_Nth_DOW(2,3,7,2009) will return the third Tuesday of 7th 2009.