Return timezone applied or 0 if not present

lib/cartodb/models/dataview/histogram.js

@@ -491,7 +491,8 @@ Histogram.prototype.format = function(result, override) {
     override = override || {};
     var buckets = [];
 
-    var aggregation = override && override.aggregation ? override.aggregation : this.aggregation;
+    var aggregation = getAggregation(override, this.aggregation);
+    var timezone = getTimezoneParam(override, this.timezone);
     var binsCount = getBinsCount(override);
     var width = getWidth(override);
     var binsStart = getBinStart(override);
@@ -513,6 +514,7 @@ Histogram.prototype.format = function(result, override) {
 
     return {
         aggregation: aggregation,
+        timezone: timezone,
         bin_width: width,
         bins_count: binsCount,
         bins_start: binsStart,
@@ -522,6 +524,20 @@ Histogram.prototype.format = function(result, override) {
     };
 };
 
+function getAggregation(override, aggregation) {
+    return override && override.aggregation ? override.aggregation : aggregation;
+}
+
+function getTimezoneParam(override, timezone) {
+    if (override && override.timezone) {
+        return override.timezone;
+    }
+    if (timezone) {
+        return timezone;
+    }
+    return 0;
+}
+
 function getBinStart(override) {
     if (override.hasOwnProperty('start') && override.hasOwnProperty('end')) {
         return Math.min(override.start, override.end);