To sync with Yahoo Calendar:
1. Go to Timeline.
2. Hit the blue "Add-to-Calendar" button.
3. Chose the Category you'd like to subscribe to.
4. Select Yahoo.
5. Hit "Copy Link" and copy the link from the pop-up.
6. Sign in to your Yahoo Calendar.
7. Click on the Settings icon in the "Others" tab.
8. Select "Follow Other Calendars" from the drop down menu.
9. Choose a title for your new calendar and paste the link address into the "iCal Address" bar.
10. Click "Continue."
Wait! Is Yahoo giving you an error message?
No good fix here - just try again, and again…. and again. It is not us! :(
Here's a demo video on how to sync with Yahoo: