Which character is known as the computer science teacher Jenny Calendar?

Jenny Calendar, the computer science teacher, is actually Janna Kalderash.

Jenny is the identity Janna uses while teaching at Sunnydale High School. Played by Robia LaMorte, she is introduced as a computer expert and a self-described “technopagan,” whose technical skills complement Rupert Giles’s traditional research methods.

Her hidden background becomes central in season two. Janna belongs to the Kalderash Romani group that restored Angel’s soul through a curse and sent her to Sunnydale to monitor him. She initially conceals this mission from Buffy, Giles, and the rest of the Scooby Gang.

A common mix-up is treating “Jennifer Calendar” as her original birth name. The series identifies her true name as Janna of the Kalderash, while “Jenny Calendar” is the identity she adopts publicly. Her relationship with Giles becomes tragic after Angel loses his soul: Angelus later kills her in “Passion.”