Clause 1.10 (term "Dark time of day")

Dark time of day — the part of the day from sunset to sunrise.

Clause 19.1

During the dark time of day and in conditions of insufficient visibility, regardless of the degree of road illumination, as well as in tunnels, all moving motor vehicles must have their low (or high) beam headlights turned on.

Clause 19.1 (note)

In conditions of insufficient visibility, it is allowed to use fog lights instead of low (or high) beam headlights on motor vehicles.

Thus, the correct answer is "The part of the day from sunset to sunrise," given that according to the definition in the Traffic Rules, the dark time of day is directly established by the term in clause 1.10.

In the theoretical exam, it is important to rely not on the feeling of "when it is already dark," but on the definition from the Rules. That is why the Traffic Rules in point 1.10 provide terms that have a clear meaning for all road users.

In point 1.10 of the Traffic Rules, the term "dark time of day" is defined by the calendar, based on the position of the sun: it is the period from the moment of sunset to the moment of sunrise. This includes the twilight after sunset, nighttime, and the morning twilight before sunrise. It does not matter whether the road is illuminated by streetlights in the city, and it does not matter how much "you can still see" with the naked eye: if the sun has already set or has not yet risen, this is considered the dark time of day according to the Traffic Rules.

The practical meaning of such a definition is simple: during this period, the driver must ensure the visibility of their vehicle to others. That is why the Rules provide for the obligation to use external lighting devices while driving during the dark time of day, so that the car is noticed in advance by other road users.

Therefore, the correct answer is "The part of the day from sunset to sunrise," since this is exactly how the Traffic Rules in point 1.10 define the "dark time of day" regardless of subjective assessment of lighting.