Need help building a Calendar UI for Android 2.2. Any suggestions on how to start?

I am building a Calendar Application for Android OS. I have previously made some Android applications with built-in android widgets such as buttons and spinners etc. Now I want to create an Android Application that displays 4 'tabbed' views of a Calendar (month, week, day & list). I have already built the backend stuff for the application, I just need to display the events in an interactive UI. I have a few questions regarding this:

1. Any suggestions on how to go about doing this? Should I have a xml file with gridview that can update in real-time according to user intera开发者_JS百科ctions + current time. If so then do you have any open-source example of this?
2. Are there any open source calendar applications I can check for Calendar UI information?
3. I have to update the Calendar UI according to the current day and time. How can I do this?

Any other suggestions are also welcome.

Thank you.

It might be of interest to take a look at the Android Calendar source.