<?php

    $termina = new \DateTime('2050-12-11 11:14:15');
    $hoje    = new \DateTime();
    
    $intervalo = $hoje->diff($termina);

    printf('%04d/%02d/%02d %02d:%02d:%02d', $intervalo->y, $intervalo->m, $intervalo->d, $intervalo->h, $intervalo->i, $intervalo->s);