The time it takes for new content from your website to indexed in googles search engines depends on the websites age and authority and how popular the website is.
The more popular websites get crawled more often from googles search engine bot and the less popular websites get crawled less often so if your website isn't all that popular then it could take up to a month or 2 before you see your new blog post or other content indexed in google.
If your website is older and more popular then you might see your new content indexed within 20 minutes.