def shift_dates(seconds)
      if (@low.is_a? DateTime) || (@low.is_a? Time)
        @low = (@low.utc.to_time + seconds.seconds).to_datetime.new_offset(0)
      end
      if (@high.is_a? DateTime) || (@high.is_a? Time)
        @high = (@high.utc.to_time + seconds.seconds).to_datetime.new_offset(0)
        @high = @high.year > 9999 ? @high.change(year: 9999) : @high
      end
      self
    end
def shift_dates(seconds)
      if (@low.is_a? DateTime) || (@low.is_a? Time)
        @low = (@low.utc.to_time + seconds.seconds).to_datetime.new_offset(0)
      end
      if (@high.is_a? DateTime) || (@high.is_a? Time)
        @high = (@high.utc.to_time + seconds.seconds).to_datetime.new_offset(0)
        @high = @high.year > 9999 ? @high.change(year: 9999) : @high
      end
      self
    end
Shift dates by the given value.
 Given value should be in seconds. Positive values shift forward, negative
 values shift backwards.

 NOTE: This will only shift if @high and @low are DateTimes.