Calculate birthdate range from dates & ages.

census_birthdate_calculator.rb

# Census Birthdate Calculator
# http://sean.famthings.com/2009/03/04/the-census-birth-date-calculator/
# http://genealogy.eshea.us/anchestor_birthdate_calculator.html

# Calculate birthdate range from dates & ages.

# Usage: ruby census_birthdate_calculator.rb 2000-04-14 16 2013-03-21 28

require 'date'

birthdate_starts = []
birthdate_ends = []

ARGV.each_slice(2) do |date, age|
  date = Date.parse(date)
  age = age.to_i

  birthdate_starts << (date.prev_year(age+1)+1)
  birthdate_ends   <<  date.prev_year(age)
end

puts "Birthday Range: #{birthdate_starts.max} - #{birthdate_ends.min}"