Animation.startTime

The Animation.startTime property of the Animation interface returns or sets the scheduled time when an animation's playback should begin. 

An animation’s start time is the time value of its DocumentTimeline when its target KeyframeEffect is scheduled to begin playback. An animation’s start time is initially unresolved.

Syntax

// getting an animation's startTime
var animationStartedWhen = animation.startTime;

// setting an animation's startTime
animation.startTime = 300;

Value

A number representing the current time in milliseconds, or null.

Examples

In the Running on Web Animations API example, the we can sync all new animated cats by giving them all the same startTime as the original running cat:

var catRunning = document.getElementById ("withWAAPI").animate(keyframes, timing);

/* A function that makes new cats. */
function addCat(){
  var newCat = document.createElement("div");
  newCat.classList.add("cat");
  return newCat;
}

/* This is the function that adds a cat to the WAAPI column */
function animateNewCatWithWAAPI() {

  // make a new cat
  var newCat = addCat();

  // animate said cat with the WAAPI's "animate" function
  var newAnimationPlayer = newCat.animate(keyframes, timing);

  // set the animation's start time to be the same as the original .cat#withWAAPI
  newAnimationPlayer.startTime = catRunning.startTime;

  // Add the cat to the pile.
  WAAPICats.appendChild(newCat);
}

Specifications

Browser compatibility

See also

• Web Animations API
• Animation
• Animation.currentTime for the current time of the animation.