Right click on the clock and choose Calendar in the pop-up menu will appear Calendar.

The window appears:

You may choose any other day for which all information is figured automatically: sunset/sunrise time, lunar day, lunar phase and others.  Press Today to return to present day automatically.

Julian day is the order number of the day from the beginning of the year.

Calendar view is the same as on the tooltip and you can set its element on the Tooltip tab.

Sunrises and sunsets are calculated for the city selected in the Your location tab. So, be sure to choose your city to get the right information.