Don't quite know where you're getting the one year bit, unless it's the matter of the voucher being good for "one year". My understanding is that you need to take most tests (or at the very least, schedule your first test-taking date) within a year of purchase, but as the Part II is a take-home... I've yet to hear of anyone "failing" out of the Part II due to a time limit.
Theodore Jonathan Casser
SCJP/SCSNI/SCBCD/SCWCD/SCDJWS/SCMAD/SCEA/MCTS/MCPD... and so many more letters than you can shake a stick at!