Firstly: Go to http://ical.dbs.ie/ and enter your DBS email address e.g. mine is eddie.ormonde@dbs.ie, you will then receive an email with your individual Calendar URL, required for instructions in step 2.

Secondly: Follow these instructions to add your timetable to your DBS calendar. 

https://celcat.wiki/en/guides/configuration_guides/version_8.1/celcat_icalendar_feed_configuration_guide/google_calendar?s[]=icalendar&s[]=google

You will now see your timetable in your calendar, should you have a change/addition to your timetable this will automatically update in your calendar but please be aware it does take a few hours to update.