Improve timezone handling:

1. Load all date/datetime values with moment.utc() which doesn't apply
   current timezone to them.
2. Don't use toLocaleString to format strings (which was converting them
   to current timezone as well).

Ref getredash#411.

handlers/static.py

@@ -36,14 +36,16 @@ def index(**kwargs):
         'permissions': current_user.permissions
     }
 
-    features = {
+    client_config = {
         'clientSideMetrics': settings.CLIENT_SIDE_METRICS,
         'allowScriptsInUserInput': settings.ALLOW_SCRIPTS_IN_USER_INPUT,
-        'highChartsTurboThreshold': settings.HIGHCHARTS_TURBO_THRESHOLD
+        'highChartsTurboThreshold': settings.HIGHCHARTS_TURBO_THRESHOLD,
+        'dateFormat': settings.DATE_FORMAT,
+        'dateTimeFormat': "{0} HH:mm".format(settings.DATE_FORMAT)
     }
 
     return render_template("index.html", user=json.dumps(user), name=settings.NAME,
-                           features=json.dumps(features),
+                           client_config=json.dumps(client_config),
                            analytics=settings.ANALYTICS)
 
 

settings.py

@@ -143,6 +143,7 @@ def all_settings():
 CLIENT_SIDE_METRICS = parse_boolean(os.environ.get("REDASH_CLIENT_SIDE_METRICS", "false"))
 # http://api.highcharts.com/highcharts#plotOptions.series.turboThreshold
 HIGHCHARTS_TURBO_THRESHOLD = int(os.environ.get("REDASH_HIGHCHARTS_TURBO_THRESHOLD", "1000"))
+DATE_FORMAT = os.environ.get("REDASH_DATE_FORMAT", "DD/MM/YY")
 
 # Features:
 FEATURE_ALLOW_ALL_TO_EDIT_QUERIES = parse_boolean(os.environ.get("REDASH_FEATURE_ALLOW_ALL_TO_EDIT", "true"))