Develop Calendar app for iPad

According to my client requirement I have assigned to develop calender app same as http://itunes.apple.com/app/momagenda/id387027303?mt=8

Please give me some idea or code from where and what I开发者_开发问答 should start.

Here's an iPhone calendar sample that might help get you started:

http://blog.webscale.co.in/?p=244