---
title: trimDuration
framework: realitykit
role: symbol
role_heading: Instance Property
path: realitykit/actionanimation/trimduration
---

# trimDuration

An optional duration that overrides the calculated duration.

## Declaration

```swift
var trimDuration: TimeInterval? { get set }
```

## Discussion

Discussion The framework calculates AnimationAction/duration, but you can set this property to override it. This property is nil by default, which indicates that the animation stops after one play that spans AnimationAction/duration. If you set a non-zero value for this property and both AnimationAction/trimStart and AnimationAction/trimEnd are nil, the animation observes this property as an edited duration. When you set AnimationAction/repeatMode to make the animation repeat: If this property is nil, the animation repeats forever. If set to a value greater than AnimationAction/duration, the animation repeats for the specified duration.