Help you one another in Al Birr and At Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression [al-Maaidah 5:2]
Besides being bidah and having no basis in shareeah, these birthday celebrations also involve imitation of the Jews and Christians in their birthday celebrations. The Prophet (peace and blessings of Allaah be upon him) said, warning us against following their ways and traditions: You would follow the ways of those who came before you step by step, to such an extent that if they were to enter a lizards hole, you would enter it too. They said, O Messenger of Allaah, (do you mean) the Jews and Christians? He said, Who else? (Reported by al-Bukhaari and Muslim). The Prophet (peace and blessings of Allaah be upon him) also said: Whoever imitates a people is one of them.
Watch this video