There's a sign in the docking bay/customs area of B5 which makes it clear
to visitors that B5 operates on Earth Standard time (or Earth Median time, or
somesuch, I forget the exact wording). Just to give it some sense of order.

Re: changing costumes...that's the funny part. See, every one of the
costumes was made to come apart, to be recombined in various ways. Our
problem was the cast, who loved the ensemble look of each item, and insisted
on wearing the whole thing. Take Londo, for instance...his outfit came with
the grand coat (his one really good coat), three shirts, three vests, two
pants, a cape and different boots. But he wanted to wear the coat at all
times, and butoned up...so you can't really SEE the change in clothes. The B5
personnel (Sinclair, Garibaldi, others) also kept wearing their clothes, which
were made to be opened, take the jacket off, relax...completely closed 99% of
the time.

This will be changed.

jms