In the URL they place qdr=w qdr=d (day) qdr=w (week) qdr=m (month) qdr=y (year). You can also search for multiples of these units, like search for pages indexed in the last 2 weeks by placing qdr=w2 in the URL string.
If you change your content management system or add new sections to your site you can see how quickly they are getting indexed, and look for any duplicate content issues as the new pages are getting indexed by looking for pages indexed under multiple URLs.
If you have never checked your site for duplicate content issues, but recently published content, that might also show any content duplication issues or Google indexed pages that you do not want in Google's index.
About the author:
Aaron Wall is the author of SEO Book, a dynamic website offering marketing tips and coverage of the search space, free SEO videos, and free SEO tools. He is a regular conference speaker, partner in Clientside SEM, and publishes dozens of independent websites.