I realize there is already a review about this here, but it's using strings and stuff rather than date objects.

I'm trying to make a simple function to calculate days from a point in time and return object(s). The days have to follow an ignore list (like weekends and holidays) to calculate a range of days, then consider itself landing on any of those ignore days/dates in the end range, then compensate to skoot the final range if needed.

After trial and error with different methods of doing this (++ iterations mostly), I settled on this function. It seems too heavy though considering (mostly) all it's doing is skipping certain ISO day numbers to do some adds. I am also not sure its working for all cases.

Are there some PHP date hidden secrets that I am missing? Or a way to boil this down? It seems like a feature such as this (skipping day codes) would be baked into PHP DatePeriod() or DateInterval() but sadly its not. How would you approach this, pref without counters/strtotime stuff, and pref without extra classes or libs?

<?php

function getWorkingDaysFrom($from, $amtOfDays) {
    $globalDays = 0; // a global addition to $amtOfDays (such as a minimum shipping time of 3 days across all objects)
    $amtOfDays = $amtOfDays + $globalDays; // set base amount of days for initial range before calculations applied
    $ignore = array('6', '7'); // days of the week to ignore (weekends are 6 & 7) in ISO-8061
    $holidays = array('*-06-13', '*-11-23', '*-12-25', '*-01-01', '*-02-29'); // holiday dates (holidays are ignored if they fall into ignore list)
    $oneDay = new DateInterval('P1D');
    $from = new DateTime($from);
    $to = new DateTime();
    $to->add(new DateInterval('P' . $amtOfDays . 'D'));

    foreach(new DatePeriod($from, $oneDay, $to) as $day) {  
        if (in_array($day->format('N'), $ignore)) {
            $to->modify('+1 day');
        } elseif (in_array($day->format('*-m-d'), $holidays)) {
            $to->modify('+1 day');
        }
        while (in_array($to->format('N'), $ignore) || (!in_array($to->format('N'), $ignore) && in_array($to->format('*-m-d'), $holidays))) {
            $to->modify('+1 day');
        }
    }
    return $to;
}

getWorkingDaysFrom('now', 20);

?>

Thanks for your time and insights.