Online PHP editor | output for pNviX

<?php $arr = array( array('from'=>'2017-07-10 15:22:45', 'to'=>'2017-07-11 16:22:46'), array('from'=>'2017-07-11 16:22:47', 'to'=>'2017-08-05 07:10:09'), array('from'=>'2017-08-05 07:10:10', 'to'=>'2017-09-22 09:25:12'), array('from'=>'2017-09-22 09:25:15', 'to'=>'2017-10-18 08:13:58'), array('from'=>'2017-10-18 08:13:58', 'to'=>'2017-11-29 13:29:12') ); $gap = false; For($i=0; $i<count($arr)-1; $i++){ $diff = strtotime ($arr[$i+1]['from']) - strtotime ($arr[$i]['to']); If($diff >1){ $gap = true; Echo "key " . $i . " to " . ($i+1) .". Missing " .$diff . " seconds"; } }