Summarize the following:
One easy way to discover someone’s birthday is to look them up on Facebook. If you have an account of your own, log in and type their name into the search bar at the top of the screen. Once you get to their profile, you should see their date of birth displayed in the info box below their profile picture.  If the person has a private account, you’ll need to become friends with them to view their info. Tap or click the “Add Friend” button next to their name to send them a friend request. If their date of birth isn’t listed in their infobox, try scanning their timeline to see if their other friends wished them a happy birthday the previous year. Just scroll down the page until you come to a group of birthday posts made on the same day. If you’re on Instagram, you may be able to learn when someone’s birthday is looking through their photos. Visit their profile page, or that of one of their good friends, and review their posts from the past year. It’s not uncommon for people to post pictures of themselves on their birthdays, so chances are good that something will turn up.  If you’re still not having any luck, try scouring a mutual friends’ posts to look for pictures of them with the person you’re looking for. Keep in mind that if the person’s page is private, you’ll have to send them a follow request and wait for them to approve it before you can access their posts. Snapchat displays a birthday cake emoji by users’ names on the birthday they specify in their info. If you’re friends with the person on Snapchat, type their name into your friend's list and see if a cake shows up next to it. You may need to do this daily for a little while if you only have a vague idea of when their birthday is.  To get a better idea of when someone’s birthday is from their Snapchat profile, check to see if they have their zodiac sign listed on their info panel. Their sign will appear as a small purple box emoji with 1 of 12 symbols inside.  If you don’t know anything about astrology, you can look up which dates of birth the person’s sign corresponds to by visiting http://snapchatemojis.com/birthdays/. Like other social media platforms, Twitter allows users to add their birthday to their info section. If the person has entered their birthday, it will appear in the upper left-hand side of their page. When their actual birthday arrives, there will be a neon balloon overlay applied to any posts they make on that day. Including your date of birth on your profile page is optional, so if the person opted not to enter theirs, you’ll have no choice but to find it out some other way.

Summary:
Pull up the person’s Facebook profile to view their info. Follow the person on Instagram and search for birthday-related posts. Look for a birthday cake emoji to appear beside their name on Snapchat. Check their Twitter profile page or look for balloons on their tweets.