St Petersburg is in the same Russia Time Zone as Moscow.
Daylight Saving Time is
observed in European Russia, where the time is shifted forward by 1 hour.
After the Summer months the time is shifted back by 1
hour to Standard Time.
Russia Time Zones
Moscow time (0)
Zone +1 (Samara)
Zone +2 (Yekaterinburg)
Zone +3 (Novosibirsk)
Zone +4 (Krasnoyarsk)
Zone +5 (Irkutsk)
Zone +6 (Chita)
Zone +7 (Vladivostok)