Remember Events

Google Calendar lets you add yearly recurring events; handy to see friends' birthdays in advance, for example. Gmail lets you add dates to your contacts; handy to note friends' birthdays, for example. Why enter the same date twice, though, for something that occurs once every year?

Conveniently, you do not have to.  Google Calendar can pick up birthdays you've added to your Gmail contacts and show them as a special schedule of all-day events—including birthday cakes.

Add Your Gmail Contacts' Birthdays to Google Calendar

To add a calendar showing and alerting you to birthdays of your Gmail contacts to Google Calendar:

Make sure the My calendars list is expanded in Google Calendar.

Now make sure the Birthdays calendar's box is filled with a color.

Click the box in front of Birthdays if it is not.

Note that you cannot add notifications—by email or SMS text message, for instance—to your Google Calendar birthday calendar.

To get alerts, you can copy individual birthdays to a personal calendar (open the event and select copy to my calendar).