parsing and validating dates in ruby. Have an icky feeling

parsing_and_validating_dates.rb

  def parse_date(date)
    if date.is_a?(Integer)
      parse_date_from_timestamp(date)
    elsif date.is_a?(String)
      if date.to_i.to_s == date
        parse_date_from_timestamp(date.to_i)
      else
        parse_date_from_string(date)
      end
    elsif date.acts_like?(:date) || date.acts_like?(:time)
      # acts_like(:date || :time) defined in activesupport/core_ext
      date
    else
      raise ArgumentError, "date can be an timestamp or a string"
    end
  end

  def parse_date_from_timestamp(timestamp)
    Time.at(timestamp)
  end

  def parse_date_from_string(date)
    # can raise TypeError
    # if for eq. we pass in a symbol - needs string
    # or can raise `ArgumentError: invalid date`
    # in case date is invalid
    Date.parse(date)
  end