What do you think, how much?
Here are options:
.... a) all "daytime" ...?
... b) While the passenger of the lower shelf does not want to sleep ...?
... c) only during meals ...?
... d) None ...
Outful passenger wrote a request to Russian Railways and received an official response to the company Blanca JSC "Federal Passenger Company"
(PFC JSC Passenger Service Management
So, the correct answer: on the basis of clause 51 of the rules of transport ....... - "d" at all!
A source