Is there any relationship between birth anniversary and birthday celebration?

From the OED entry for birthday:

2. On the day before one’s birthday one year after one’s birth your father’s

current birthday is his 89th. The Anniversary or annual observance of the day of birth of any one… Therefore one’s birthday occurs one year after one’s birth, and your father’s birthday is his 13th.

What is East Asian age reckoning and how in some cultures does it

differ from the way in some cultures; for example: East Asian age reckoning is a concept and practice that originated in China and is widely used by other cultures in East Asia. Every year a new born woman starts to become their own age and at the New Years Day she will be three by the age of forty. In other words, the first year of life is counted as one instead of zero.

What is your view on the world?