---
title: "init(startTime:duration:parameter:)"
framework: realitykit
role: symbol
role_heading: Initializer
path: "realitykit/actioneventdefinition/init(starttime:duration:parameter:)"
---

# init(startTime:duration:parameter:)

Constructs an event definition.

## Declaration

```swift
init(startTime: TimeInterval, duration: TimeInterval, parameter: ActionEventDefinition<ActionType>.EventParameterType? = nil)
```

## Parameters

- `startTime`: The time when the event becomes active.
- `duration`: The duration of the event.
- `parameter`: The event parameter to return to the event handler when the event occurs.