Open the Facebook app on your iPhone or iPad. The Facebook icon looks like a white "f" in a blue square. You can find it on your home screen, or in a folder on your home screen. If you're not automatically logged in, enter your email or phone, and your password to sign in. Tap the Menu icon. This button looks like three horizontal lines in the lower-right corner of your screen. It will open your navigation menu. Scroll down and tap Events. This option is listed next to a red-and-white calendar icon. Tap the CALENDAR tab on the Events page. This button is at the top of your screen. It will open your Facebook calendar, and show a chronological list of all your saved events. Scroll down and find your friend's name next to a birthday cake icon. All of your friends' birthdays are automatically added to your calendar. If you see a cake icon next to a friend's name on the calendar, this means it's their birthday.