--- a/devtools/client/inspector/animation/animation.js
+++ b/devtools/client/inspector/animation/animation.js
@@ -372,17 +372,18 @@ class AnimationInspector {
   }
 
   removeAnimationsCurrentTimeListener(listener) {
     this.animationsCurrentTimeListeners =
       this.animationsCurrentTimeListeners.filter(l => l !== listener);
   }
 
   async rewindAnimationsCurrentTime() {
-    await this.setAnimationsCurrentTime(0, true);
+    const { timeScale } = this.state;
+    await this.setAnimationsCurrentTime(-1 * timeScale.zeroPositionTime, true);
   }
 
   selectAnimation(animation) {
     this.inspector.store.dispatch(updateSelectedAnimation(animation));
   }
 
   async setSelectedNode(nodeFront) {
     if (this.inspector.selection.nodeFront === nodeFront) {
@@ -450,17 +451,17 @@ class AnimationInspector {
         await this.inspector.target.actorHasMethod("animations", "pauseSome");
     }
 
     let { animations, timeScale } = this.state;
 
     try {
       if (doPlay && animations.every(animation =>
                       timeScale.getEndTime(animation) <= animation.state.currentTime)) {
-        await this.doSetCurrentTimes(0);
+        await this.doSetCurrentTimes(-1 * timeScale.zeroPositionTime);
       }
 
       // If the server does not support pauseSome/playSome function, (which happens
       // when connected to server older than FF62), use pauseAll/playAll instead.
       // See bug 1456857.
       if (this.hasPausePlaySome) {
         if (doPlay) {
           await this.animationsFront.playSome(animations);

--- a/devtools/client/inspector/animation/test/browser_animation_pause-resume-button_end-time.js
+++ b/devtools/client/inspector/animation/test/browser_animation_pause-resume-button_end-time.js
@@ -3,38 +3,41 @@
 
 "use strict";
 
 // Test whether the animation can rewind if the current time is over end time when
 // the resume button clicked.
 
 add_task(async function() {
   await addTab(URL_ROOT + "doc_simple_animation.html");
-  await removeAnimatedElementsExcept([".animated", ".end-delay", ".long"]);
+  await removeAnimatedElementsExcept([".animated",
+                                      ".end-delay",
+                                      ".long",
+                                      ".negative-delay"]);
   const { animationInspector, panel } = await openAnimationInspector();
 
   info("Check animations state after resuming with infinite animation");
   info("Make the current time of animation to be over its end time");
   await clickOnCurrentTimeScrubberController(animationInspector, panel, 1);
   info("Resume animations");
   await clickOnPauseResumeButton(animationInspector, panel);
   await wait(1000);
   assertPlayState(animationInspector.state.animations,
-                  ["running", "finished", "finished"]);
+                  ["running", "finished", "finished", "finished"]);
   await clickOnCurrentTimeScrubberController(animationInspector, panel, 0);
 
   info("Check animations state after resuming without infinite animation");
   info("Remove infinite animation");
   await setClassAttribute(animationInspector, ".animated", "ball still");
   info("Make the current time of animation to be over its end time");
   await clickOnCurrentTimeScrubberController(animationInspector, panel, 1);
   await clickOnPlaybackRateSelector(animationInspector, panel, 10);
   info("Resume animations");
   await clickOnPauseResumeButton(animationInspector, panel);
-  assertPlayState(animationInspector.state.animations, ["running", "running"]);
+  assertPlayState(animationInspector.state.animations, ["running", "running", "running"]);
   assertCurrentTimeLessThanDuration(animationInspector.state.animations);
   assertScrubberPosition(panel);
 });
 
 function assertPlayState(animations, expectedState) {
   animations.forEach((animation, index) => {
     is(animation.state.playState, expectedState[index],
        `The playState of animation [${ index }] should be ${ expectedState[index] }`);

--- a/devtools/client/inspector/animation/test/browser_animation_rewind-button.js
+++ b/devtools/client/inspector/animation/test/browser_animation_rewind-button.js
@@ -4,17 +4,17 @@
 "use strict";
 
 // Test for following RewindButton component:
 // * element existence
 // * make animations to rewind to zero
 // * the state should be always paused after rewinding
 
 add_task(async function() {
-  await addTab(URL_ROOT + "doc_custom_playback_rate.html");
+  await addTab(URL_ROOT + "doc_multi_timings.html");
   const { animationInspector, panel } = await openAnimationInspector();
 
   info("Checking button existence");
   ok(panel.querySelector(".rewind-button"), "Rewind button should exist");
 
   info("Checking rewind button makes animations to rewind to zero");
   await clickOnRewindButton(animationInspector, panel);
   assertAnimationsCurrentTime(animationInspector, 0);

--- a/devtools/client/inspector/animation/utils/timescale.js
+++ b/devtools/client/inspector/animation/utils/timescale.js
@@ -21,16 +21,17 @@ class TimeScale {
     if (!animations.every(animation => animation.state.createdTime)) {
       // Backward compatibility for createdTime.
       return this._initializeWithoutCreatedTime(animations);
     }
 
     let animationsCurrentTime = -Number.MAX_VALUE;
     let minStartTime = Infinity;
     let maxEndTime = 0;
+    let zeroPositionTime = 0;
 
     for (const animation of animations) {
       const {
         createdTime,
         currentTime,
         delay,
         duration,
         endDelay = 0,
@@ -55,21 +56,23 @@ class TimeScale {
                          duration * (iterationCount || 1) +
                          Math.max(endDelay, 0));
       }
 
       minStartTime = Math.min(minStartTime, startTime);
       maxEndTime = Math.max(maxEndTime, endTime);
       animationsCurrentTime =
         Math.max(animationsCurrentTime, createdTime + toRate(currentTime));
+      zeroPositionTime = Math.min(zeroPositionTime, (minStartTime - createdTime));
     }
 
     this.minStartTime = minStartTime;
     this.maxEndTime = maxEndTime;
     this.currentTime = animationsCurrentTime;
+    this.zeroPositionTime = zeroPositionTime;
   }
 
   /**
    * Same as the constructor but doesn't use the animation's createdTime property
    * which has only been added in FF62, for backward compatbility reasons.
    *
    * @param {Array} animations
    */
@@ -110,45 +113,42 @@ class TimeScale {
       const endTime = previousStartTime + length;
       this.maxEndTime = Math.max(this.maxEndTime, endTime);
 
       this.documentCurrentTime = Math.max(this.documentCurrentTime, documentCurrentTime);
     }
   }
 
   /**
-   * Convert a distance in % to a time, in the current time scale.
-   *
-   * @param {Number} distance
-   * @return {Number}
-   */
-  distanceToTime(distance) {
-    return this.minStartTime + (this.getDuration() * distance / 100);
-  }
-
-  /**
-   * Convert a distance in % to a time, in the current time scale.
-   * The time will be relative to the current minimum start time.
+   *  Convert a distance in % to a time, in the current time scale. The time
+   *  will be relative to the zero position time.
+   *  i.e., If zeroPositionTime will be negative and specified time is shorter
+   *  than the absolute value of zero position time, relative time will be
+   *  negative time.
    *
    * @param {Number} distance
    * @return {Number}
    */
   distanceToRelativeTime(distance) {
-    const time = this.distanceToTime(distance);
-    return time - this.minStartTime;
+    return (this.getDuration() * distance / 100)
+           + this.zeroPositionTime;
   }
 
   /**
    * Depending on the time scale, format the given time as milliseconds or
    * seconds.
    *
    * @param {Number} time
    * @return {String} The formatted time string.
    */
   formatTime(time) {
+    // Ignore negative zero
+    if (Math.abs(time) < (1 / 1000)) {
+      time = 0.0;
+    }
     // Format in milliseconds if the total duration is short enough.
     if (this.getDuration() <= TIME_FORMAT_MAX_DURATION_IN_MS) {
       return getFormatStr("timeline.timeGraduationLabel", time.toFixed(0));
     }
 
     // Otherwise format in seconds.
     return getFormatStr("player.timeLabel", (time / 1000).toFixed(1));
   }