Two Options depending on what calendar system you use:
Option 1 : Manually configure your personal calendar to subscribe to one or more calendars by clicking the blue "Copy ICS Link" button to copy the ".ics" link to the clipboard then paste the link into your calendar. Each calendar has its' own set of instructions for subscribing to external calendars and the most common can be found here.
Option 2 : iPhone\iPad\Mac users that also use Apple Calendar as their personal calendar have the option to click the subscribe link. If for some reason the Subscribe method doesn't work then use the manual method.