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:
- Select Settings | Calendar settings in Google Calendar.
- Go to the Calendars tab.
- Follow the Browse interesting calendars » link under Other Calendars.
- Open the More tab.
- Click Subscribe for Contacts' birthdays and events.
Note that you cannot add notifications — by email or SMS, for instance — to your Google Calendar birthday calendar. You can get an RSS feed of upcoming birthdays, though.
To get alerts, you can also copy individual birthdays to a personal calendar (open the event and select copy to my calendar).