I would like to book the visit of the top of the Rock, but I don't know if the validity of the card counts from the day I make the reservation or from the day of the reservation.

It is valid from the first day you use it. We didnt pre book the top of the rock we went to the ticket office on the day. The added benefit is if it's a cloudy day the views arent as good. So you can choose a clear day to go.

It starts the first day that you redeem the pass at an attraction!