All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
It is allowed for a Muslim to celebrate special occasions, such as birthday, graduation, and wedding anniversary since rejoicing in the bounty of Allah and His mercy is lawful in Islam. Allah the Almighty says: " Say: "In the bounty of God. And in His Mercy,- in that let them rejoice": that is better than the (wealth) they hoard." {Younis, 58}.
The Messenger of Allah (Peace be upon him) was asked about fasting on Mondays. He said, "That is the day on which I was born and the day on which I received Revelation." {Related by Muslim}. His fasting on Mondays (Day in which he was born)is an act of rejoicing and showing gratitude to Allah, and this the basis on which scholars ruled that it is allowed for a Muslim to celebrate special occasions of his/her personal life.
Ruling that a certain act is haram (Forbidden) without an evidence from Sharia is going so strict and ascribing false things to Allah. Allah the Almighty reproached such people where He said {what means}: "But say not - for any false thing that your tongues may put forth,- "This is lawful, and this is forbidden," so as to ascribe false things to God. For those who ascribe false things to God, will never prosper." {An-Nahl, 116}. In addition, there are lots of Quranic verses indicating this.
Some rule that a certain act is forbidden-although there is no evidence from Sharia that it is as such-just because the Prophet (Peace be upon him) and his companions didn`t do it, however, scholars have made clear that not everything that the Prophet (Peace be upon him) didn`t do is forbidden.
Nonetheless, the controls of Sharia must be applied when celebrating personal occasions: No mixing between men and women who aren`t immediate relatives, women must adhere to the Islamic code of dress, no uncovering of Awrahs (Private parts), chastity is maintained, and no privacy between the men and the women.
There is nothing wrong with exchanging gifts on these occasions since this is an act of Sunnah at every time it is given. Narrated Abu Hurairah:
The Messenger of Allah (Peace be upon him) would accept a present, but would not accept alms (sadaqah)." {Related by Abu Dawoud}. And Allah the Almighty knows best.