timeline: set weekday css class on high zoom levels; fixes #2014;

code cleanup;

lib/timeline/TimeStep.js

@@ -588,37 +588,47 @@ TimeStep.prototype.getClassName = function() {
 
   switch (this.scale) {
     case 'millisecond':
-      return even(current.milliseconds()).trim();
+      return today(current) +
+        even(current.milliseconds()).trim();
 
     case 'second':
-      return even(current.seconds()).trim();
+      return today(current) +
+        even(current.seconds()).trim();
 
     case 'minute':
-      return even(current.minutes()).trim();
+      return today(current) +
+        even(current.minutes()).trim();
 
     case 'hour':
-      var hours = current.hours();
-      if (this.step == 4) {
-        hours = hours + '-h' + (hours + 4);
-      }
-      return 'vis-h' + hours + today(current) + even(current.hours());
+      return 'vis-h' + current.hours() + (this.step == 4 ? '-h' + (current.hours() + 4) : '') +
+        today(current) +
+        even(current.hours());
 
     case 'weekday':
       return 'vis-' + current.format('dddd').toLowerCase() +
-          today(current) + currentWeek(current) + even(current.date());
+        today(current) +
+        currentWeek(current) +
+        even(current.date());
 
     case 'day':
-      var day = current.date();
-      var month = current.format('MMMM').toLowerCase();
-      return 'vis-day' + day + ' vis-' + month + currentMonth(current) + even(day - 1) + (this.step <= 2 ? today(current) +' vis-' + current.format('dddd').toLowerCase() : '');
+      return 'vis-day' + current.date() +
+        ' vis-' + current.format('MMMM').toLowerCase() +
+        today(current) +
+        currentMonth(current) +
+        this.step <= 2 ? today(current) : '' +
+        this.step <= 2 ? ' vis-' + current.format('dddd').toLowerCase() : '' +
+        even(current.date() - 1);
 
     case 'month':
       return 'vis-' + current.format('MMMM').toLowerCase() +
-          currentMonth(current) + even(current.month());
+        currentMonth(current) +
+        even(current.month());
 
     case 'year':
       var year = current.year();
-      return 'vis-year' + year + currentYear(current)+ even(year);
+      return 'vis-year' + year +
+        currentYear(current) +
+        even(year);
 
     default:
       return '';