Ezra Miller's Barry Allen really is the fastest man alive, and might be arriving in theaters one week earlier than planned. According to Exhibitor Relations, Warner Brothers has moved their DC film slotted for March 23rd, to March 16th, 2018.

UNTITLED DC FILM (possibly FLASH) will streak into multiplexes a week earlier than planned--3/16/18 instead of 3/23. — Exhibitor Relations (@ERCboxoffice) February 9, 2016

Back when WB and DC first announced their slate of movies, The Flash was the first movie to come out in 2018, and since there is no other WB/DC Films movie on the schedule before March 16th, we're pretty sure Exhibitor Relations is right in their assumption that this is the film we're talking about.