iso8601

# File activesupport/lib/active_support/values/time_zone.rb, line 389
    def iso8601(str)
      # Historically `Date._iso8601(nil)` returns `{}`, but in the `date` gem versions `3.2.1`, `3.1.2`, `3.0.2`,
      # and `2.0.1`, `Date._iso8601(nil)` raises `TypeError` https://github.com/ruby/date/issues/39
      # Future `date` releases are expected to revert back to the original behavior.
      raise ArgumentError, "invalid date" if str.nil?

      parts = Date._iso8601(str)

      year = parts.fetch(:year)

      if parts.key?(:yday)
        ordinal_date = Date.ordinal(year, parts.fetch(:yday))
        month = ordinal_date.month
        day = ordinal_date.day
      else
        month = parts.fetch(:mon)
        day = parts.fetch(:mday)
      end

      time = Time.new(
        year,
        month,
        day,
        parts.fetch(:hour, 0),
        parts.fetch(:min, 0),
        parts.fetch(:sec, 0) + parts.fetch(:sec_fraction, 0),
        parts.fetch(:offset, 0)
      )

      if parts[:offset]
        TimeWithZone.new(time.utc, self)
      else
        TimeWithZone.new(nil, self, time)
      end

    rescue Date::Error, KeyError
      raise ArgumentError, "invalid date"
    end