TimeTravel.php

<?php
    class TimeTravel {
        private $start;
        private $end;
        
        public function __construct($start, $end) {
            $this->start = $start;
            $this->end = $end;
        }

        public function getTravelInfo() {
            $interval = date_diff($this->start, $this->end);
            return 'Il y a'.$interval->format('%y').' années, '.$interval->format('%m').' mois, '.$interval->format('%d').' jours, '.$interval->format('%h') .' heures, '.$interval->format('%i').' minutes et '.$interval->format('%s').' secondes entre les deux dates\n';
        }

        public function findDate($interval) {
            $dateToFind = new DateTime("1985-12-31");
            $dateToFind->sub($interval);
            return 'Doc est bloqué le '.$dateToFind->format('d/m/y').'\n';
        }

        public function backToFutureStepByStep(DatePeriod $period){
            echo 'Etape à saisir dans le converteur temporel : \n';
            foreach ($period as $date){
                echo $date->format('M j Y A h:i').'\n';
            }
        }
    }
?>

travel.php

<?php
    include 'TimeTravel.php';

    $startDate = new DateTime('1998-07-12 12:13:40');
    $endDate = new DateTime('2018-07-15 12:13:45');

    $timeTravel = new timeTravel($startDate, $endDate);
    echo $timeTravel->getTravelInfo();

    $temporalGap = new DateInterval('PT1000000000S');
    echo $timeTravel->findDate($temporalGap);

    $start = new DateTime('2010-07-01');
    $step = new DateInterval('P1M1W1D');
    $end = new DateTime();
    $period = new DatePeriod($start, $step, $end);

    $timeTravel->backToFutureStepByStep($period);
?>