(Source: http://visit-petersburg.invest.gov.spb.ru)

If you can't find any possibility to visit some exhibitions during the daytime, there is no need to worry. Here you will find a list of museums in St. Petersburg that are open for the visitors in the evening. Moreover, some of them are even free of charge. 

One of the most visited museums in St. Petersburg - the Catherine Palace in Pushkin – now lets the visitors in until 9 p.m. Thus, the three great classic museums in St. Petersburg are working longer than until the usual time on some days of the week. The usual working hours of the St. Petersburg museums are from 9-10 a.m. to 6-7 p.m. Until recently, the exceptions to these old-fashioned rules were only the new museum institutions which worked longer from the very beginning.

The Museum of Contemporary Art "Erarta", for example, is open until 10 p.m., and "The Horrors of St. Petersburg" Museum which is popular among tourists closes at 9 p.m.

Extending the working hours of the federal museums was suggested by the Minister of Culture of the Russian Federation Vladimir Medinsky in June 2012.

The State Hermitage grasped the idea very quickly: since 1 July of the last year it began to work until 9 p.m. on Saturdays, and since October 3 there were already two "extended" days at the museum (Wednesday and Saturday). At present this mode of work is accepted by the Russian Museum (on Thursdays it is open until 9 p.m.) and also by the famous Amber Room in the Catherine Palace (until 9 p.m. on Mondays). However, the Russian Museum is open not from 10 a.m., but from 1 p.m. on the "extended" Thursdays. The remaining museums which are a part of the "Tsarskoye Selo State Museum-Reserve” in Pushkin didn`t change their working hours. In addition, the last Monday of the month at the Catherine Palace is a cleaning day, so on this day the museum is completely closed to the public.

Few people know that a number of museums of the northern capital provide free access. Thus, the State Hermitage Museum, the Museum of the Imperial Porcelain Factory and the Russian Ethnographic Museum are open for free on the first Thursday of each month (only for the children up to 18 years on the last Thursday). The Museum of the History of Religion accepts the visitors for free every first Monday of the month, and the Puppet Museum does it on the last Monday. Suvorov Museum lets everyone in for free on the first Sunday of the month, and the Navy Museum does it on the last Wednesday. The Pushkin Apartment Museum is free for visitors on February 10 and June 6, and the Pushkin Lyceum is open for free visits on June 6 and October 19.