When to expect my rich snippets to appear after applying a schema markup?

Schema is great but requires some time to show results. Hence, we’d like to let you know and give you a heads-up: you will start seeing rich snippets on SERPs once Google bots crawl your updated page. Until then, you won’t see immediate results. 

However, there is a way of notifying Google of the adjustments you made yourself. You can request Google to put your pages in a queue to be reindexed. This is called a sitemap.