The calendar allows you to view by month or day. To view by day, on the right just above the calendar click on the icon that has a single date on it.To view by month, click on the other icon that looks like a full calendar.
To move around the calendar, use the <- -> and <<- ->> arrows at the top,. The current month selected will show inbetween the arrows. The single > moves by month. The doulbe moves by year. You can click 'today' to bring the calendar back to today.
