The offset, in seconds, in the playlist where the last uninterrupted period of playback began.
- iOS 4.3+
- macOS 10.7+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 6.0+
The property corresponds to “c-start-time".
The value of this property is negative if unknown.
This property is not compatible with Key-value observing.