It is easy to have Notifications show birthdays by entering the date of birth in the appropriate field in Contacts. However, there seems to be no way to add anniversaries. I found a workaround, however. A young couple married in July and my wife and I want to be reminded of their anniversary. Yes, I could enter it into Calendar, but that's a one-time entry that would have to be done for each year.
Here's the workaround:
Create a new contact in Contacts. In the last name field, type the last name of the couple. Then, type "anniversary" in the first name field. Now, enter the anniversary date in the Birthday field. Voilà! Calendar now shows the last name followed by "anniversary" and Notifications will give you advance warning.
