.vis-even / .vis-odd not available on Timeline

[knokit]

.vis-even and .vis-odd are not available on Timeline when the zoom level is equal to days.

On the following example, zoom out one level and inspect the time-axis elements (vis-even/vis-odd classes disappeared): http://visjs.org/examples/timeline/basicUsage.html

Also, the classes used for days are different from what is described in the documentation: http://visjs.org/docs/timeline/#Styles
Docs say it should be vis-date1 but the timeline renders vis-day1.

[mojoaxel]

Two issues:

1. bug in the timeline docs. Should be vis-day1, vis-day2 ...
2. classes vis-even and vis-odd don't get added in some zoom levels.

[bradh]

The vis-even / vis-odd should be resolved as part of #2909