For people who work late, putting on a good film late in the evening must be a good thing. There was always complaints in the past that there was only dross on in the early hours of the night/day.
As others have said above, the film has been shown at earlier times in the past. To show the film at the same time every time that it is on is only going to reach the same audience.
By you own admission, you want people to see this great film, so why not show it at different times of the day/night to reach a wider audience.