<?php

function validar_horas($hora) 
{
   $formato = 'H:i';

   $data = date_create_from_format('!'. $formato, $hora);

   return $data && $data->format($formato) === $hora;
}


$arr = array('00:00', '19:59', '20:34', '24:33', '22:64', '07:59', '000:30', '30:50', '99:99');

foreach($arr as $item) var_dump(validar_horas($item));