Before a site goes live, check the pages a buyer will actually use. Titles, forms, the inbox those forms reach, and the confirmation a person sees. Check it on a phone. Check that editors can change a page without breaking the layout.
Also check speed on the important templates, basic security updates, and that search can find the addresses you intend to publish. Remove sample content.
Launch when that list is done. A launch date that skips it is a public draft.