How long do you get to ask for a replacment..?

[siam]

I am looking at buying an Apple iMac here in Thailand, and the Apple reseller has told me that I have One week to take it back if there's a problem and want it replaced, Ive just noticed a post from some one in the UK , and it seem's in the UK you get Two Weeks to take the machine back, and the new machine comes with a One year warranty as all Mac's do , I was just wondering why there's a take back Time period difference , surely if all Apple Mac's have a One year warranty, and if you buy AppleCare any where in the world every one gets the same Two years extra warranty, why is it that here in Thailand we only get One Week to return the computer, and another country gets Two weeks, a Mac is a Mac where ever you live ..?