Automatic luggage lockers at all Moscow and St. Petersburg railway stations are open 24/7. Moreover, you can leave your luggage at left-luggage offices - most of them work day and night as well (at Belorussky Railway Station, Leningradsky Railway station, Kazansky Station, Kievsky Station, Paveletsky Station in Moscow and at Moskovsky Station, Vitebsky Station, Finlandsky Station, Ladojsky Station in St. Petersburg).