The DocumentTimeline interface of the Web Animations API represents animation timelines, including the default document timeline (accessed via Document.timeline).
The currentTime read-only property of the Web Animations API's AnimationTimeline interface returns the timeline's current time in milliseconds, or null if the timeline is inactive.
The
DocumentTimelineinterface of the Web Animations API represents animation timelines, including the default document timeline (accessed via Document.timeline).MDN Reference