Facebook has a feature that lets you add your business hours to pages you admin. See: How can People order Food from my Restaurant Through my Facebook Page?
4. Click Edit Page Info.
5. Click the Hours tab at the top.
6. Add your hours and click Save Changes.
Note that if you don’t see an Hours section on your page, you may need to change your Page’s category.
See: How can People order Food from my Restaurant Through my Facebook Page?
How do I add business hours to my Facebook Page?