Avengers: Doomsday currently has two dates attached to its UK and Ireland release: Wednesday, Dec. 16, and Friday, Dec. 18. The earlier date appears in Digital Cinema Media's calendar; the later date remains in Disney UK's July announcement.
Walt Disney Studios Motion Pictures International is named as the film's UK and Ireland distributor in the DCM entry. The Dec. 16 date appears directly beneath the film title.
The July 20 Disney UK announcement repeats Dec. 18 three times: in the headline, opening paragraph and closing release information. The two official dates remain two days apart.
See the current DCM film calendar and Disney UK release announcement.