   Adds a specified amount of time to a `NaiveDateTime`.
 
   Accepts an `integer` in any `unit` available from `t:System.time_unit/0`.
-  Negative values will be move backwards in time.
+  Negative values will move backwards in time.
 
   This operation is only possible if both calendars are convertible to `Calendar.ISO`.
 

  The NaiveDateTime struct contains the fields year, month, day, hour,
  minute, second, microsecond and calendar. New naive datetimes can be
  built with the `new/2` and `new/7` functions or using the
  [`~N`](`Kernek.sigil_N/2`) sigil:

      iex> ~N[2000-01-01 23:00:07]
      ~N[2000-01-01 23:00:07]

  `NaiveDateTime` is not validated against a time zone, such errors
  would go unnoticed.

  The functions of this module work with the `NaiveDateTime` struct as well
  as any struct that contains the same fields as the `NaiveDateTime` struct,
  such as `DateTime`. Such functions expect
  `t:Calendar.naive_datetime/0` in their typespecs (instead of `t:t/0`).

  Developers should avoid creating the NaiveDateTime structs directly
  and instead, rely on the functions provided by this module as well
  as the ones in 3rd party calendar libraries.

  ## Comparing naive date times
