php获取当天的零点和24点（即当天的00:00:00~23:59:59）

$todayStart= date('Y-m-d 00:00:00', time()); //2016-11-01 00:00:00

$todayEnd= date('Y-m-d 23:59:59', time()); //2016-11-01 23:59:59