# `Stripe.Params.InvoiceCreatePreviewParams.ScheduleDetails.Phases.Duration`
[🔗](https://github.com/jeffhuen/tiger_stripe/blob/main/lib/stripe/params/invoice_create_preview_params.ex#L488)

Nested parameters.

# `t`

```elixir
@type t() ::
  %Stripe.Params.InvoiceCreatePreviewParams.ScheduleDetails.Phases.Duration{
    interval: String.t() | nil,
    interval_count: integer() | nil
  }
```

* `interval` - Specifies phase duration. Either `day`, `week`, `month` or `year`. Possible values: `day`, `month`, `week`, `year`.
* `interval_count` - The multiplier applied to the interval.

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