# `Moar.NaiveDateTime`
[🔗](https://github.com/synchronal/moar/blob/main/lib/naive_datetime.ex#L1)

NaiveDateTime-related functions. See also `Moar.DateTime`.

# `add`

```elixir
@spec add(NaiveDateTime.t(), Moar.Duration.t()) :: NaiveDateTime.t()
```

Like `NaiveDateTime.add/2` but takes a `Moar.Duration`.

See also `subtract/1` and `Moar.DateTime.add/2`.

> #### Note {: .info}
>
> This function is naive and intentionally doesn't account for real-world calendars and all of their complexity,
> such as leap years, leap days, daylight saving time, past and future calendar oddities, etc.
>
> As ["Falsehoods programmers believe about time"](https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b923ca)
> says, "If you think you understand everything about time, you're probably doing it wrong."
>
> See [`Cldr.Calendar.plus/2`](https://hexdocs.pm/ex_cldr_calendars/Cldr.Calendar.html#plus/2) for one example
> of a function that is far more likely to be correct.

```elixir
iex> start = ~N[2022-01-01T00:00:00.000]
iex> Moar.NaiveDateTime.add(start, {3, :minute})
~N[2022-01-01T00:03:00.000]
```

# `from_iso8601!`

```elixir
@spec from_iso8601!(date_time_string :: String.t()) :: NaiveDateTime.t()
```

Like `NaiveDateTime.from_iso8601/1` but raises if the string cannot be parsed.

```elixir
iex> Moar.NaiveDateTime.from_iso8601!("2022-01-01T00:00:00")
~N[2022-01-01T00:00:00]

iex> Moar.NaiveDateTime.from_iso8601!("2022-01-01T00:00:00+0800")
~N[2022-01-01T00:00:00]

iex> Moar.NaiveDateTime.from_iso8601!("Next Thursday after lunch")
** (ArgumentError) Invalid ISO8601 format: "Next Thursday after lunch"
```

# `subtract`

```elixir
@spec subtract(NaiveDateTime.t(), Moar.Duration.t()) :: NaiveDateTime.t()
```

Subtracts `duration` from `date_time`.

See also `add/1` and `Moar.DateTime.subtract/2`.

> #### Note {: .info}
>
> This function is naive and intentionally doesn't account for real-world calendars and all of their complexity,
> such as leap years, leap days, daylight saving time, past and future calendar oddities, etc.
>
> As ["Falsehoods programmers believe about time"](https://gist.github.com/timvisee/fcda9bbdff88d45cc9061606b4b923ca)
> says, "If you think you understand everything about time, you're probably doing it wrong."
>
> See [`Cldr.Calendar.minus/4`](https://hexdocs.pm/ex_cldr_calendars/Cldr.Calendar.html#minus/4) for one example
> of a function that is far more likely to be correct.

```elixir
iex> start = ~N[2022-01-01T00:03:00.000]
iex> Moar.NaiveDateTime.subtract(start, {3, :minute})
~N[2022-01-01T00:00:00.000]
```

# `to_iso8601_rounded`

```elixir
@spec to_iso8601_rounded(date_time :: NaiveDateTime.t()) :: String.t()
```

Like `NaiveDateTime.to_iso8601/1` but rounds to the nearest second first.

```elixir
iex> Moar.NaiveDateTime.to_iso8601_rounded(~N[2022-01-01T01:02:03.456789])
"2022-01-01T01:02:03"
```

# `utc_now`

```elixir
@spec utc_now([{:plus, Moar.Duration.t()}] | [{:minus, Moar.Duration.t()}]) ::
  NaiveDateTime.t()
```

Returns the current UTC time plus or minus the given duration.

```elixir
iex> Moar.NaiveDateTime.utc_now(plus: {10500, :millisecond})
...> |> Moar.Duration.format([:approx, :from_now])
"10 seconds from now"

iex> Moar.NaiveDateTime.utc_now(minus: {10, :second})
...> |> Moar.Duration.format([:approx, :ago])
"10 seconds ago"
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*