Hongkong airport travel pass - double airport journey + 3 days consecutive mtr travel

When does the 3 consecutive days start. If you use it single journey out fr airport to Tsing Yi station. Then, if i use to go to Olympic station (thats considered activating the card and that means another 2 days left..correct? When you top up..its after the 3rd day? If you suggest to top up on arrival..does that mean you don't activate the 3 days??

Also, how does the card get recognised for the return airport journey?