Hi,
According to me, Google changes very often as, we cant say at what time it will crawl your web site may be your site will get crawl in 24 hrs or can take a long time.
All you need to focus, on having quality, rich and fresh content and also regular updates in your content which increases no. of unique visits on your site. Also, it is important to have link popularity that is quality and relevant backlinks.
Also, your site must contain sitemap.
Thanks!!
