Every other day at lunchtime.

We'll find a suitable day.

Added 5 minutes later

Taking the train to Sochi isn't a great idea – spending a day in a stuffy carriage when a plane isn't much more expensive is for masochists.

There's nothing stuffy about it, Sasha, you're spreading misinformation! The train to Sochi is quite comfortable, especially the sleeper carriages. You've probably forgotten when you last took the train to Sochi. It's longer, yes, I agree, but it's fun, no traffic, a peaceful journey by land, you can lie down and stretch your legs, and no transfers to and from the airport (you get out in the city center and it's a short distance to your destination).