Hi - I don't know any specific sources to suggest, but wanted to warn
you that schedules might well be irrelevant for this period. This was
during a period of armed conflict between the Reds, Whites and others
for leadership of Russia, between Russia and Poland regarding an
independent Poland and its borders, and between Poland and Lithuania
for control of Vilna and Suwalki provinces. A fictionalized memoir I
just read describeid the trains as running hours behind schedule when
they ran and that sections of track and bridges were sometimes
destroyed by warring factions.
Probably your best bet is to find a memoir by someone who lived in
that area at that time and see if train travel is mentioned.