To solve this question we have to make deduct these 2 years. 2099 minus 1979 will give the answer.
You are 120 years old.
(1440 months are passed.)
From 1979 to 2099 there are 120 years. If you want to learn your age in 2099 (born in 1979) your age is 120.
Let's see what will be your age if you born +1 or -1 from that date.