Have a look at this document ... http://shared.xara.com/diNpZUgi2O/ ... Specifically the section "When do my 365 days start?" the summary of which is

... If you are renewing an Update Service then the new 365 days will start from expiry date of your current Update Service, even if you purchase sooner. This allows you to take advantage of promotion offers before your current Update Services expires ...

So you should be good.