[Supernowaa]

My analogy is, how do apple know the invoice date automatically, because iphones are sold by local stores too. I think the date starts from the day you switch on the mobile.

Seller in my country literally stock the iphones from local distributors, they dont even have a direct contacts to apple nor distributor also after the sell.

Oh, I thought its from the date you start the service. 

Apple's terms can be somewhat confusing, but It Is from the purchase date.

Let's think about It logically. If you don't activate your device for 20 years and a short time after that you decide to do so, Is It still covered by warranty from that date? I'm not targeting this at yourself, but rather demonstrating an analogy for warranty purposes.