想问下,我有两天的假期英语应该怎么说呢 i have a two-day holiday i have a two days' holiday

想问下,我有两天的假期英语应该怎么说呢 i have a two-day holiday i have a two days' holiday
i have a two-day holiday
i have a two days' holiday
这两句哪个对呢,加不加那个A呢
请告之,