Children's Day

I was wondering if Children's Day (which is celebrated in Brazil on October, 12th) already existed when I was a child, since I recall getting presents only on my birthday and on Christmas.
I did a quick search and found that this date was officialized by a decree signed by president Arthur Bernardes in 1924, but that it only started being celebrated on the sixties, when a toy manufacturer decided to honor the children (and to increase sales, of course) promoting the date instituted by that decree.
Even knowing that this is just more a commercial promotion than a spontaneous celebration, how can we not give presents to the children, who expect them on this date? And specially, how not to give presents to a grandson who is celebrating his first Children's Day?
Guilherme got many presents today. He probably didn't understand the reason, but he surely liked it! And he also loved to cut his cake!