Yes, that is quite possible. In fact, with several billion people on Earth, it's practically inevitable.
A birthday is an anniversary of the day that someone was born, or the date upon which a person was born.
If someone was born in 2044, they will celebrate their 100th birthday in 2144.
King Davis or someone
Someone born October 23, 2000 was 12 years old on their birthday in 2012. They turn 13 on their birthday in 2013, and 14 on their birthday in 2014.
Someone born in 1973 will turn 38 on his birthday in 2011, and 39 on his birthday in 2012.
They were born in 1912.
It depends on your birthday, If your birthday has passed this year, you are 18 If not - 17.
Someone born in 1977 turned 36 on their birthday in 2013, and ... - 37 on their birthday in 2014 - 38 on their birthday in 2015 - 39 on their birthday in 2016 - 40 on their birthday in 2017
birthday is a celebration of birth. wishing someone a happy birthday, is to say have a happy "anniversary" of you being born.
someone born in 1928would have an 89th birthday in 2017
Their birthday is on February 29th. (On a leap year)
Someone who turns 34 on their birthday in 2012 was born in 1978. 2012 - 34 = 1978