In the realm of contract, things get their plain meaning, unless defined in the contract. And ambiguity goes against the contract drafter.... so:
http://www.google.com/search?sourceid=navclient&ie=UTF-8&rls=GGLD,GGLD:2004-51,GGLD:en&q=define%3a+week
If we look at various definitions, your understanding is more correct.
Lawyer.
JD, 10 years representing clients, 75+ Trials