- preg_match: documentation ( source)
- date: documentation ( source)
<?php
$datestr = 'Fri, 28 Feb 2020 19:18:26 +010';
$date = new DateTime($datestr);
$tz = preg_match('/([+-]\d+)$/', $datestr, $m) ? $m[0] : '';
$now = new DateTime(date('Y-m-d H:i:s ' . $tz));
$now->modify('-1 day');
if ($now > $date) {
echo "$datestr is more than 1 day ago\n";
}