Many people who live in the United States and Canada think of Mexico as the land of Mañana. A place where getting things done on any particular schedule is simply not that important.
My experience is that anything that Mexicans may lack in punctuality, they more than make up for in warmth. Sometimes, when a Mexican says he will do something or show up at a given time, he really means, “I like you.”
And after all, who can complain about people liking you!
“No abras el regalo todavía, es para mañana” means it’s not for now, it’s for later (tomorrow).