Answers for "php time constants day seconds"

php get elapsed time

// microtime(true) returns the unix timestamp plus milliseconds as a float
$starttime = microtime(true);
/* do stuff here */
$endtime = microtime(true);
$timediff = $endtime - $starttime;

php strtotime 1 day ago from

date('Y-m-d', strtotime('+1 day', strtotime($date)))