Ruby program to take birth year and tells age

Following program shows you how to take birth year and tells age.
In this program we get birth year from user and tells their age using Date.today.year - birthYear

require 'date'
puts "Please enter your date of birth:"
birthYear = Integer(gets.chomp)
age = Date.today.year - birthYear
puts "Your age is #{age}"

Output:

Please enter your date of birth:
 1960
Your age is 58