Receiving a Gifted Item

I'm sorry if this has been asked already. I'm still pretty new to this site. So, I'm wondering if as soon as someone buys an NX item, say like a 2x exp. card if the timer starts running AS SOON as it's bought or as soon as it's been received by entering the cash shop. Please, I need to know ASAP because if it's the 1st, I'm deeply screwed. *2x card running*

Again, sorry if it's been repeatedly asked.