‘The Big Bang Theory’: When is Sheldon Cooper’s Birthday?

The main characters of The Big Bang Theory have a lot in common. Not only do the four main male characters work at the same university, but they are all geniuses who seemingly had traumatic upbringings. Both Sheldon Cooper and Leonard Hofstader have issues with their birthdays, so much so that it was initially pretty challenging to pin down the actual day of Sheldon’s birth. Thankfully, the 200th episode of the show cleared up any confusion, but a plothole does exist.

When is Sheldon Cooper’s birthday?

It is revealed that Sheldon was born on February 26, 1980. The reveal came during the 200th episode of the series when Amy Farrah Fowler wants to throw a party to celebrate Sheldon’s birthday. Sheldon, ever the enigma, explains that he doesn’t acknowledge his birthday because Adam West never showed up at his childhood party. West is the man who played Batman.

Jim Parsons as Sheldon Cooper
Sheldon Cooper (Jim Parsons) | Michael Yarish/CBS via Getty Images

The Batman incident occurred when Sheldon was six and was apparently a prank perpetrated by Sheldon’s sister Missy. Sheldon and Missy are twins, but unlike Sheldon, Missy was socially adept. While she often had parties with friends, Sheldon was left out. Amy and the gang set out to make Sheldon’s 36th birthday the best possible. Since the episode took place in 2016, Sheldon would be turning 40 in February 2020.

Penny inadvertently changed Sheldon’s birthday

Everyone now knows that Sheldon was born in February, but that’s not the way it always was. Penny once suggested that Sheldon was a Taurus, claiming he fit the astrological sign perfectly. There is a little problem with that; the astrological sign Penny assigns to Sheldon is nowhere near correct.

According to the Sun, Taurus is the astrological sign assigned to individuals born between April 21 and May 21. Since we know that Sheldon’s birthday is at the end of February, his real astrological sign is Pisces. The Pisces symbol is assigned to anyone born between Feb. 19 and March 20.

Penny states that Sheldon is a Taurus in the very first season of the show. She notes that she is aware of his birthday because she read his horoscope for him. In a later season, when Sheldon reveals that it’s his birthday, Penny remarks that she would have never pegged him as a Pisces.

Sheldon’s birthday isn’t the only plot hole in the show

For a show that ran as long as The Big Bang Theory a few plotholes are expected, but there are more than a few associated with Sheldon specifically. For example, Sheldon claims a severe allergy to cats. The allergy is spoken about when Leonard brings home a scratching post. Leonard, desperate to have a feline companion, claims he worked out a way around the problem. The fact remains, however, that Sheldon is allergic to cats.

Later on, when Sheldon has a minor breakdown, he brings home several cats. He never seems to have an allergy to those cats, though. He also keeps the cats in his bedroom with him. Several cats in such a small place would inevitably trigger an allergic person.

Sheldon also alleges he doesn’t know how to dance several times through the series. He claims that he has no desire to learn. There is a little problem with that statement, though; Sheldon later reveals that he was forced to take Cottilion classes as a young boy in Texas. Cotillion classes include learning to dance, so it would stand to reason that Sheldon knows more than he is letting on about dancing. Did he simply lie about his experience, or did the writers forget that Sheldon has a severe lack of dance moves?