Another simple way to calculate the difference in minutes. Please note this is a sample for calculating within a 1-year range. for more details click here
$origin = new DateTime('2021-02-10 09:46:32');
$target = new DateTime('2021-02-11 09:46:32');
$interval = $origin->diff($target);
echo (($interval->format('%d')*24) + $interval->format('%h'))*60; //1440 (difference in minutes)