When can I apply for citizenship? green card dates are confusing...

[infoseeker1234]

My greencard dates show the following
Card expires -> 06/20/2012
Resident since -> 04/03/2002

Can I apply for citizenship now? Or do I have to wait till end of May? How is the 90 day thing calculated?

Thanks

[rsr]

You can apply now. In fact you could apply after Jan 2, 2007.