check periods crosses another period

period.php

<?php

class Period extends \DatePeriod
{
    public function crosses(\DatePeriod $period)
    {
        return $this->numbers_cross(
            strtotime($this->getStartDate()->format('Y-m-d')),
            strtotime($this->getEndDate()->format('Y-m-d')),
            strtotime($period->getStartDate()->format('Y-m-d')),
            strtotime($period->getEndDate()->format('Y-m-d'))
        );
    }
    
    private function numbers_cross($min1, $max1, $min2, $max2)
    {
	return ($min1 >= $min2 && $min1 <= $max2) || ($max1 <= $max2 && $max1 >= $min2);
    }
}

function getPeriod($sFrom, $sTo)
{
	try {
		$oPeriod = new \Period(
			new \DateTime(date("Y-m-d", strtotime($sFrom))),
			new \DateInterval('P1D'),
			new \DateTime(date("Y-m-d", (strtotime($sTo))))
		);
	} catch (\Exception $e) {
		return null;
	}

	return $oPeriod;
}

$p1 = getPeriod('01-01-2020', '03-01-2020');
$p2 = getPeriod('02-01-2020', '04-01-2020');


echo $p1->crosses($p2) ? "yes" : 'no'; // yes