How to replicate Finder Smart Folders

I am looking to replicate the smart folder feature of the finder which show: - files modified in during the day - Files modified teh day before - All images files - All movies files ...

I know it is using spotlight but w开发者_StackOverflow中文版hat are the queries behind this?

Thanks and regards,

---

Create a search query in the finder and save it as a smart folder. The “folder” can then be opened in a text editor – it’s an XML file containing the Spotlight query and additional semantic data describing the search window.