Based on a bi-weekly pay cycle, determine which months you will receive an extra paycheck.

extra_paycheck_calculation.rb

require 'active_support/time'

def paycheck_count(begin_date, years)

  month_count = {}
  end_date = begin_date + years.years
  time_counter = begin_date

  while time_counter < end_date do
    key = "#{time_counter.year}.#{time_counter.month}"
    if month_count[key]
      month_count[key] += 1
    else
      month_count[key] = 1
    end
    time_counter += 2.weeks
  end

  month_count.map{|year_month, count| year_month if count > 2}.compact
end

puts "#{paycheck_count(Date.new(2017,9,8), 5).join(' ')} have extra paychecks"