timestamp.rb

require "time"

class Timestamp
  attr_reader :time

  private_class_method :new

  def initialize(time)
    fail TypeError.new("String required") unless time.is_a?(String)
    @time = Time.parse(time)
  end

  def self.from_string(time_string)
    new(time_string)
  end

  def to_s
    time.to_s
  end

  def equals(t2)
    self.time == t2.time
  end

  def before(t2)
    self.time < t2.time
  end

  def after(t2)
    self.time > t2.time
  end
end