require 'date'
 
range = (Date.today-7)..(Date.today)
 
dates = ['2015-12-02','2015-12-03','2015-12-14','2015-12-19','2015-12-21','2015-12-23']
 
dates.each do |date|
  date = Date.parse(date)
  if range.include?(date)
    puts date
  end
end