Step 1: Go to the web version of Google Calendar — at calendar.google.com. There, you can manually add the calendar. This should be done on your desktop.
Step 2: Log into the web app with your Google ID. Once you are inside, you should see "Other Calendars" on the left sidebar. There should be a drop-down arrow next to it. Click it and choose "Add by URL".
Step 3: Once the window pops up and asks you to add a URL, paste the following URL into the bar:
Now Press "Add Calendar".
Refresh the page and give it a few minutes. You will notice that the schedule will be available across Google Calendar on all your devices. The best part is that all the dates and timings will be converted into your time zone.
Tip: In case the calendar does not appear on your tablet or smartphone's Google Calendar. Open the Calendar App > Press the options/settings button > Calendars to Display > Add 'World Cup 2014'.
It will automatically update as teams qualify and teams get sent home. Sadly, I'm not expecting too much England action in July.