diff --git a/lib/torque/animator.js b/lib/torque/animator.js
index b83fbb6..263b5c9 100644
--- a/lib/torque/animator.js
+++ b/lib/torque/animator.js
@@ -26,31 +26,11 @@
       maxDelta: 0.2,
       loop: true
     });
-    
 
-    this.domain = invLinear(this.options.animationDelay, this.options.animationDelay + this.options.animationDuration);
-    this.range = linear(0, this.options.steps);
-  }
-
-
-  function clamp(a, b) {
-    return function(t) {
-      return Math.max(Math.min(t, b), a);
-    };
-  }
-
-  function invLinear(a, b) {
-    var c = clamp(0, 1.0);
-    return function(t) {
-      return c((t - a)/(b - a));
-    };
-  }
-
-  function linear(a, b) {
-    var c = clamp(a, b);
-    return function(t) {
-      return c(a*(1.0 - t) + t*b);
-    };
+    this.domainInv = torque.math.linear(this.options.animationDelay, this.options.animationDelay + this.options.animationDuration);
+    this.domain = this.domainInv.invert();
+    this.range = torque.math.linear(0, this.options.steps);
+    this.rangeInv = this.range.invert();
   }
 
 
@@ -76,6 +56,11 @@
       }
     },
 
+    step: function(s) {
+      if(arguments.length === 0) return this.range(this.domain(this._time));
+      this._time = this.domainInv(this.rangeInv(s));
+    },
+
     pause: function() {
       this.running = false;
       cancelAnimationFrame(this._tick);
@@ -86,7 +71,7 @@
       var delta = (t1 - this._t0)*0.001;
       // if delta is really big means the tab lost the focus
       // at some point, so limit delta change
-      delta = Math.min(this.options.maxDelta, delta)
+      delta = Math.min(this.options.maxDelta, delta);
       this._t0 = t1;
       this._time += delta;
       var t = this.range(this.domain(this._time));
diff --git a/lib/torque/gmaps/torque.js b/lib/torque/gmaps/torque.js
index 7ee5287..8c49012 100644
--- a/lib/torque/gmaps/torque.js
+++ b/lib/torque/gmaps/torque.js
@@ -6,6 +6,7 @@ function GMapsTorqueLayer(options) {
   var self = this;
   this.key = 0;
   this.cartocss = null;
+  this.ready = false;
   this.options = _.extend({}, options);
   _.defaults(this.options, {
     provider: 'sql_api',
@@ -40,8 +41,9 @@ function GMapsTorqueLayer(options) {
  * torque layer
  */
 GMapsTorqueLayer.prototype = _.extend({}, 
-  CanvasLayer.prototype, 
+  CanvasLayer.prototype,
   torque.GMapsTileLoader.prototype,
+  torque.Event,
   {
 
   providers: {
@@ -94,17 +96,6 @@ GMapsTorqueLayer.prototype = _.extend({},
     var canvas = this.canvas;
     canvas.width = canvas.width;
     var ctx = canvas.getContext('2d');
-    /*
-    ctx.fillStyle = 'white';
-    var offset = this._map.getProjection().fromLatLngToPoint(this.getTopLeft());
-    ctx.translate(-offset.x, -offset.y);
-    ctx.fillRect(0, 0, 100, 100);
-
-    var a = document.getElementsByTagName('img');
-    for(var i = 0; i < a.length; ++i) {
-      a[i].style.border = '1px solid red';
-    }
-    */
 
     // renders only a "frame"
     for(t in this._tiles) {
@@ -122,20 +113,44 @@ GMapsTorqueLayer.prototype = _.extend({},
    */
   setKey: function(key) {
     this.key = key;
+    this.animator.step(key);
     this.redraw();
+    this.fire('change:time', { time: this.getTime(), step: this.key });
   },
 
   /**
    * helper function, does the same than ``setKey`` but only 
    * accepts scalars.
    */
-  setTime: function(time) {
+  setStep: function(time) {
     if(time === undefined || time.length !== undefined) {
       throw new Error("setTime only accept scalars");
     }
     this.setKey(time);
   },
 
+  /**
+   * transform from animation step to Date object 
+   * that contains the animation time
+   *
+   * ``step`` should be between 0 and ``steps - 1`` 
+   */
+  stepToTime: function(step) {
+    if (!this.provider) return 0;
+    var times = this.provider.getKeySpan();
+    var time = times.start + (times.end - times.start)*(step/this.options.steps);
+    return new Date(time*1000);
+  },
+
+  /**
+   * returns the animation time defined by the data
+   * in the defined column. Date object
+   */
+  getTime: function() {
+    return this.stepToTime(this.key);
+  },
+
+
 
   /**
    * set the cartocss for the current renderer
diff --git a/lib/torque/leaflet/leaflet_tileloader_mixin.js b/lib/torque/leaflet/leaflet_tileloader_mixin.js
index 4acb420..995bceb 100644
--- a/lib/torque/leaflet/leaflet_tileloader_mixin.js
+++ b/lib/torque/leaflet/leaflet_tileloader_mixin.js
@@ -44,16 +44,18 @@ L.Mixin.TileLoader = {
   },
 
   _removeOtherTiles: function (bounds) {
-      var kArr, x, y, key;
+      var kArr, x, y, z, key;
+      var zoom = this._map.getZoom();
 
       for (key in this._tiles) {
           if (this._tiles.hasOwnProperty(key)) {
               kArr = key.split(':');
               x = parseInt(kArr[0], 10);
               y = parseInt(kArr[1], 10);
+              z = parseInt(kArr[2], 10);
 
               // remove tile if it's out of bounds
-              if (x < bounds.min.x || x > bounds.max.x || y < bounds.min.y || y > bounds.max.y) {
+              if (zoom !== z || x < bounds.min.x || x > bounds.max.x || y < bounds.min.y || y > bounds.max.y) {
                   this._removeTile(key);
               }
           }
diff --git a/lib/torque/leaflet/torque.js b/lib/torque/leaflet/torque.js
index 473c7a0..68ed548 100644
--- a/lib/torque/leaflet/torque.js
+++ b/lib/torque/leaflet/torque.js
@@ -3,7 +3,6 @@
  */
 L.TorqueLayer = L.CanvasLayer.extend({
 
-
   providers: {
     'sql_api': torque.providers.json,
     'url_template': torque.providers.jsonarray
@@ -61,23 +60,11 @@ L.TorqueLayer = L.CanvasLayer.extend({
     canvas.width = canvas.width;
     var ctx = canvas.getContext('2d');
 
-    if(typeof this.key === 'number') {
-      // renders only a "frame"
-      for(t in this._tiles) {
-        tile = this._tiles[t];
-        pos = this.getTilePos(tile.coord);
-        ctx.setTransform(1, 0, 0, 1, pos.x, pos.y);
-        this.renderer.renderTile(tile, this.key, pos.x, pos.y);
-      }
-    } else {
-      // accumulate more than one
-      for(t in this._tiles) {
-        tile = this._tiles[t];
-        pos = this.getTilePos(tile.coord);
-        var accum = this.renderer.accumulate(tile, this.key);
-        ctx.setTransform(1, 0, 0, 1, pos.x, pos.y);
-        this.renderer.renderTileAccum(accum, 0, 0);
-      }
+    for(t in this._tiles) {
+      tile = this._tiles[t];
+      pos = this.getTilePos(tile.coord);
+      ctx.setTransform(1, 0, 0, 1, pos.x, pos.y);
+      this.renderer.renderTile(tile, this.key, pos.x, pos.y);
     }
 
   },
@@ -89,20 +76,48 @@ L.TorqueLayer = L.CanvasLayer.extend({
    */
   setKey: function(key) {
     this.key = key;
+    this.animator.step(key);
     this.redraw();
+    this.fire('change:time', { time: this.getTime(), step: this.key });
   },
 
   /**
    * helper function, does the same than ``setKey`` but only 
    * accepts scalars.
    */
-  setTime: function(time) {
+  setStep: function(time) {
     if(time === undefined || time.length !== undefined) {
       throw new Error("setTime only accept scalars");
     }
     this.setKey(time);
   },
 
+  /**
+   * transform from animation step to Date object 
+   * that contains the animation time
+   *
+   * ``step`` should be between 0 and ``steps - 1`` 
+   */
+  stepToTime: function(step) {
+    var times = this.provider.getKeySpan();
+    var time = times.start + (times.end - times.start)*(step/this.options.steps);
+    return new Date(time*1000);
+  },
+
+  /**
+   * returns the animation time defined by the data
+   * in the defined column. Date object
+   */
+  getTime: function() {
+    return this.stepToTime(this.key);
+  },
+
+  /**
+   * returns an object with the start and end times
+   */
+  getTimeSpan: function() {
+    var times = this.provider.getKeySpan();
+  },
 
   /**
    * set the cartocss for the current renderer
@@ -116,6 +131,8 @@ L.TorqueLayer = L.CanvasLayer.extend({
 
 });
 
+//_.extend(L.TorqueLayer.prototype, torque.Event);
+
 
 L.TiledTorqueLayer = L.TileLayer.Canvas.extend({
 
diff --git a/lib/torque/provider.json.js b/lib/torque/provider.json.js
index b73370b..23eac58 100644
--- a/lib/torque/provider.json.js
+++ b/lib/torque/provider.json.js
@@ -25,7 +25,7 @@
     if (options.resolution === undefined ) throw new Error("resolution should be provided");
     if (options.steps === undefined ) throw new Error("steps should be provided");
     if(options.start === undefined) {
-      this.getKeySpan();
+      this._fetchKeySpan();
     } else {
       this._ready = true;
     }
@@ -210,12 +210,21 @@
       });
     },
 
+    getKeySpan: function() {
+      return {
+        start: this.options.start,
+        end: this.options.end,
+        step: this.options.step,
+        steps: this.options.steps
+      };
+    },
+
     //
     // the data range could be set by the user though ``start``
     // option. It can be fecthed from the table when the start
     // is not specified.
     //
-    getKeySpan: function() {
+    _fetchKeySpan: function() {
       var max_col, min_col, max_tmpl, min_tmpl;
 
       if (this.options.is_time){
@@ -233,13 +242,14 @@
         max_col: max_col,
         min_col: min_col,
         table: this.options.table
-      })
+      });
 
       var self = this;
       this.sql(sql, function(data) {
         //TODO: manage bounds
         data = data.rows[0];
         self.options.start = data.min;
+        self.options.end = data.max;
         self.options.step = (data.max - data.min)/self.options.steps;
         self._setReady(true);
       }, { parseJSON: true });
@@ -247,7 +257,7 @@
 
   };
 
-  torque.providers.json = json
+  torque.providers.json = json;
 
 
 })(typeof exports === "undefined" ? this : exports);