When is the birthday? If you want to give a cherry tree you have grown from seed you will need to start in the Autumn two or three of years ahead of the date. IF you can get the seed to grow and all goes well you will be able to offer a tree about two feet tall in about three years time. Also you will have no way of knowing what kind of cherry will grow from the seed unless you have chosen one of the wild species. You can't grow any of the ornamental flowering or good fruit bearing cherries from seed. In fact many of the double cherries don't even produce seed as the sexual parts of the flowers have mutated through hybridization into extra petals. These instructions tell you how to grow any of the wild species.

Here is a link that might be useful: Growing cherry trees from seed.