+ * Convert a JS date to a string appropriate to display on an axis that
+ * is displaying values at the stated granularity.
+ * @param {Date} date The date to format
+ * @param {Number} granularity One of the Dygraph granularity constants
+ * @return {String} The formatted date
+ * @private
+ */
+Dygraph.dateAxisFormatter = function(date, granularity) {
+ if (granularity >= Dygraph.MONTHLY) {
+ return date.strftime('%b %y');
+ } else {
+ var frac = date.getHours() * 3600 + date.getMinutes() * 60 + date.getSeconds() + date.getMilliseconds();
+ if (frac == 0 || granularity >= Dygraph.DAILY) {
+ return new Date(date.getTime() + 3600*1000).strftime('%d%b');
+ } else {
+ return Dygraph.hmsString_(date.getTime());
+ }
+ }
+}
+
+/**