I signed a lease that was to start on feb 1 2012 and end on jan 29 2012... now the landlord wants me out or to sign a new lease... is this legal

Its legal for him to ask. But you are under no legal compulsion to sign. You have ( I assume) a properly executed lease. If so, he can't force you to change it.

However, why is he doing it? Maybe there is a benefit to you in signing. Or maybe you can negotiate something that will benefit you.

i... to start on feb 1 2012 and end on jan 29 2012. ...

Very short lease, running backward in time?

Maybe that's why he wants to change it, to correct the dates. If that's the reason and there are no other changes, then go ahead. Or you can just correct the lease and both of you initial the correction.