<!--
{
  "availability" : [
    "iOS: -",
    "iPadOS: -",
    "macCatalyst: -",
    "macOS: -",
    "tvOS: -",
    "visionOS: -"
  ],
  "documentType" : "symbol",
  "framework" : "AudioToolbox",
  "identifier" : "/documentation/AudioToolbox/kAudioOutputUnitProperty_StartTime",
  "metadataVersion" : "0.1.0",
  "role" : "Global Variable",
  "symbol" : {
    "kind" : "Global Variable",
    "modules" : [
      "Audio Toolbox"
    ],
    "preciseIdentifier" : "c:@Ea@kAudioOutputUnitProperty_CurrentDevice@kAudioOutputUnitProperty_StartTime"
  },
  "title" : "kAudioOutputUnitProperty_StartTime"
}
-->

# kAudioOutputUnitProperty_StartTime

A write-only `AudioOutputUnitStartAtTimeParams` data structure valid on the audio unit global scope. When this property is set on an output unit, it will cause the next Start request (but no subsequent Starts) to use the AudioDeviceStartAtTime function, using the specified timestamp, passing false for `inRequestedStartTimeIsInput`.

```
var kAudioOutputUnitProperty_StartTime: AudioUnitPropertyID { get }
```

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)