Mark your calendars. The CW just announced the premiere dates for their upcoming crossover event for Supergirl, The Flash, and Arrow.

The three-night special will see the introduction of Batwoman (Ruby Rose) and include characters from the network’s many DC Comics series.

The CW‘s crossover event begins with a special episode of The Flash on December 9th at 8 p.m. ET/PT and continues with Arrow on December 10th at 8 p.m. ET/PT and concludes with a new episode of Supergirl on December 11th at 8 p.m. ET/PT.

See the poster below:

What do you think? Do you watch all three CW series? Are you excited for the crossover event?