Fix out of range bug in date histograms

lib/cartodb/models/dataview/histogram.js

@@ -198,8 +198,8 @@ var dateBasicsQueryTpl = dot.template([
 var dateOverrideBasicsQueryTpl = dot.template([
     '__cdb_basics AS (',
     '    SELECT',
-    '        max({{=it._end}}) AS __cdb_max_val,',
-    '        min({{=it._start}}) AS __cdb_min_val,',
+    '        max({{=it._end}})::float AS __cdb_max_val,',
+    '        min({{=it._start}})::float AS __cdb_min_val,',
     '        avg(date_part(\'epoch\', {{=it._column}})) AS __cdb_avg_val,',
     '        min(',
     '           date_trunc(',

test/acceptance/dataviews/histogram.js

@@ -332,6 +332,21 @@ describe('histogram-dataview for date column type', function() {
             });
         });
 
+        it('should cast overridden start and end to float to avoid out of range errors ' + test.desc, function (done) {
+            var params = {
+                start: -2145916800,
+                end: 1009843199
+            };
+
+            this.testClient = new TestClient(mapConfig, 1234);
+            this.testClient.getDataview(test.dataviewId, params, function (err, dataview) {
+                assert.ok(!err, err);
+                assert.equal(dataview.type, 'histogram');
+                assert.ok(dataview.bin_width > 0, 'Unexpected bin width: ' + dataview.bin_width);
+
+                done();
+            });
+        });
 
         it('should return same histogram ' + test.desc, function (done) {
             var params = {