Entering Russia is difficult these days, and the bus schedules are uncertain too, as is the queue to St Petersburg from Helsinki - which is my route. If I'm fortunate and there are no queues, I might end up on the Russian side of the Finland/Russia border before my visa is valid. My visa becomes valid at 00:01 on 1. April, but I might at the earliest show up at the Russian border checkpoint at 31.03 23:00.
Will I be denied entry for an hour? Or worse, told to gtfo and never come into Russia again?