Extract the answer to the following question from the movie plot. If the question isn't answerable, please output "Can't answer". Question: On what birthday are the twins reunited? Title: Twitches Movie plot: In the magical land of Coventry, the royal witch Miranda gives birth to identical twin daughters on the night of Halloween. The sisters are named Apolla and Artemis after the Olympian twins Apollo and Artemis, the gods of the Sun and Moon, respectively; in accordance with their namesake, Apolla wears an amulet in the shape of the sun and Artemis wears an amulet in the shape of the moon. Their father Aron DuBaer, a powerful warlock, transfers the entirety of his magical powers to protect them from an evil entity known as the Darkness and is killed in the process. Karsh and Ileana assume the task of protecting the twins and flee to a non-magical dimension known as Earth to give them up for adoption. Apolla is adopted by a wealthy couple who name her Camryn Elizabeth Barnes, while Artemis is adopted by a single mother and is named Alexandra "Alex" Nicole Fielding. Alex grows up to be an night owl and stays up until the moon sets, writing about the chronicles of magical twin sisters, unaware that her stories are true. She shares a single bedroom with her close friend Lucinda, after mother passes away a few months prior to her 21st birthday. Meanwhile, Camryn is a passionate artist and a lark, who wakes up at sunrise to sketch realistic pictures; unbeknownst to her, the images she creates are of Miranda and her homeland Coventry. She is spoiled and outgoing, unlike her quiet and reclusive sister; however, the duo share the traits of kindness and intelligence. On their 21st birthday, Camryn and her best-friend Beth decide to shop, while Alex tries to look for a job. After Karsh and Ileana manipulate Alex into entering the store where Camryn is trying on clothes, the sisters finally encounter each other. Although Camryn is overjoyed to discover Alex, the latter flees the store, prompting the former to grasp her hand. As their magic is released, they discover that they share a sisterly bond and attempt to understand each other. Karsh and Ileana reveal themselves to the twins and inform them about their magical...
Answer:
21st