Thanks.

My PM often have postdated lease signed with tenants (e.g. the lease starts on 9/1/14, the lease is signed on 9/3/14). I thought this was common practice until I read your reply.
However, your current reply also confuses me, "When he refused to sign your new lease, you could tell him he needs to move out in 30 days, or sign the new lease", does it mean a postdated lease is acceptable?