To give credit, I found this site, http://www.productivecatholic.com/how-to-easily-add-the-catholic-liturgical-calendar-to-google-calendar/
Scroll to the bottom of the page and click on the Add to Google Calendar button. Also, if you want to add the liturgical year to Outlook or another desktop or online calendar system you can download the calendar in vcalendar/ical format and then import.
You will be taken to your Google Calendar page where it will ask you if you want to add it to your calendar. Just ensure that you are only adding the items to one calendar – if you add them to multiple calendars that you are subscribed to, you will receive multiple reminders. And, it is time consuming to delete those entries since there is one for each day of the year.
Click Yes – and – voila – you have the liturgical year on your Google Calendar.
One other suggestion for families that have multiple calendars that they share – create a new calendar called Catholic Feast Days, or whatever you wish, and then add the liturgical calendar to that specific calendar. Everyone can subscribe to that calendar without worrying about receiving multiple reminders.