The CW has announced season finale dates for most of its Arrowverse shows, in addition to Black Lightning, Riverdale and iZombie. With the exception of Supergirl, all of these shows will conclude in April and May.
DC's Legends of Tomorrow will wrap up first, ending its third season on Monday, April 9. Once Legends of Tomorrow comes to a close, Supergirl will take over that time slot beginning Monday, April 16 and run through Monday, June 18. The week following the Legends of Tomorrow Season 3 finale, Black Lightning's Season 1 finale will air on Tuesday, April 17.
The rest of the Arrowverse will conclude in May, beginning with Arrow Season 6 on Thursday, May 17. The Flash will wrap the following week on Tuesday, May 22. Meanwhile, Riverdale will air its Season 2 finale on Wednesday, May 16. iZombie, another one of The CW's comic book-based shows, finishes up on Monday, May 28.
Until then, Legends of Tomorrow airs Mondays at 8 pm ET/PT; iZombie on Mondays at 9 pm ET/PT; The Flash on Tuesdays at 8 pm ET/PT; Black Lightning on Tuesdays at 9 pm ET/PT; Riverdale on Wednesdays at 8 pm ET/PT; and Arrow on Thursdays at 9 pm ET/PT.