# `Ash.Type.DurationName`
[🔗](https://github.com/ash-project/ash/blob/v3.23.1/lib/ash/type/duration_name.ex#L5)

An interval of time, primarily meant to be used in expression functions

Valid intervals are (as strings or atoms): [:year, :month, :week, :day, :hour, :minute, :second, :millisecond, :microsecond]

# `t`

```elixir
@type t() ::
  :microsecond
  | :millisecond
  | :second
  | :minute
  | :hour
  | :day
  | :week
  | :month
  | :year
```

# `handle_change?`

# `prepare_change?`

---

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