You might be interested in some previous threads on the matter of birthdays:

• How have birthdays been celebrated in history? - 41 comments, over 2 years old.
• The commenters address European birthday celebrations in very broad strokes, but with some details that may interest you.
• How long have humans been celebrating birthdays? - 12 comments, over 1 year old.
• The commenters talk about mentions and celebrations of birthdays in Antiquity.
• Does the modern popularity of birthday gift-giving owe in any significant way to the story of Jesus and the three wise men, gold frankincense and myrrh, and all that? Or was the story a tie-in to something that's been popular all along? - 9 comments, over 1 year old.
• The main question is barely answered, but there are some answers about the transition of birthday traditions as Japan modernized and westernized in the Meiji period as well as some information about the Romans.