In Calendar, you can view your calendar by day, week, month, year or even as a list of events. You can also set the default view for your calendar.
Go to Calendar.

Select the Calendar tool from the Tool Menu in your site.
Select the desired view in the drop-down menu.

Set default view of calendar.

If you have a preferred view (e.g., weekly view), click the Set as Default View button while viewing the calendar in your preferred view.