<?php
echo "-----HOJE----" . PHP_EOL;
$today = new DateTime('2017-06-08'); // Com timestamp a hora sera incluida
$days = new DateTime('2017-06-08');
$interval = $today->diff($days)->format('%d');
$hour = $today->diff($days)->format('%H:%i:%s');
echo $interval == 0 ? "Hoje às {$hour}" :
($interval == 1 ? "Ontem às {$hour}" :
"{$interval} dias atrás") . PHP_EOL;
echo "-----ONTEM----" . PHP_EOL;
$today = new DateTime('2017-06-08'); // Com timestamp a hora sera incluida
$days = new DateTime('2017-06-07');
$interval = $today->diff($days)->format('%a');
$hour = $today->diff($days)->format('%H:%i:%s');
echo $interval == 0 ? "Hoje às {$hour}" :
($interval == 1 ? "Ontem às {$hour}" :
"{$interval} dias atrás") . PHP_EOL;
echo "-----DIAS ATRAS----" . PHP_EOL;
$today = new DateTime('2017-06-08'); // Com timestamp a hora sera incluida
$days = new DateTime('2017-04-05');
$interval = $today->diff($days)->format('%a');
$hour = $today->diff($days)->format('%H:%i:%s');
echo $interval == 0 ? "Hoje às {$hour}" :
($interval == 1 ? "Ontem às {$hour}" :
"{$interval} dias atrás");