You can change your calendar settings in the page menu on the Calendar page. Click on the "Calendar settings" option:
In that menu, you'll find the option to select your location to set the timezone. Underneath the time zone, select your preferred format for the date and time. Using the option below time format, select a "First day of the week" for the week calendar view to start on a particular day, and set the default event duration below that. Be sure to hit save after making any changes!