"SHADOWHUNTERS - ""By The Light Of Dawn"" - Valentine's plan is in full effect and the Shadowhunters must act fast to save the Downworld in ""By the Light of Dawn,"" the spring finale of ""Shadowhunters,"" airing MONDAY, MARCH 6 (8:00 – 9:01 p.m. EST), on Freeform. (Freeform/John Medland) HARRY SHUM JR., KATHERINE MCNAMARA"