src/DateInterval.php
public function getSeconds()
    {
        $sec = $this->s;
        $sec += ($this->i * 60);
        $sec += ($this->h * 3600);
        $sec += empty($this->days) ? ($this->d * 86400) : ($this->days * 86400);
        return $sec;
    }
public function getSeconds()
    {
        $sec = $this->s;
        $sec += ($this->i * 60);
        $sec += ($this->h * 3600);
        $sec += empty($this->days) ? ($this->d * 86400) : ($this->days * 86400);
        return $sec;
    }
Retorna o número de segundos do intervalo
@return int