The Sanskrit word for birthdays is Jayanti. Jayanti means the pinnacle of victory. Victory is always associated with duality, war, conflict, but birth is beyond conflict because it is celebration. This is when the ocean became the wave and will become ocean again after some years. A birthday is a time to remember that the Atman (Soul/Self) was free at one time, then took name and form and became an individual being. After so many years once again the wave will go back to the ocean.
Therefore a birthday is a time for the wave to remember its magnanimity; it’s true nature that it is part of the universal spirit, divinity. Then the atman gets the strength of the ocean.
On Birthdays here we don’t blow out candles but light lamps. We move from light to light. We rejoice in the memory of our true nature and pray for more and more victory in all aspects of our life so that we can do more service. Knowledge is when we remain happy in our true nature, which is love.
No celebration is complete without meditation. Meditation helps to seep the celebration/ happiness deeper into our being. So meditate 5-7 minutes whenever you celebrate.