Day

Only what is described in the Road Traffic Regulations (RVV) is the correct legal definition. The CBR wants to confuse you with incorrect answers like: From half an hour before and half an hour after. Don’t be confused!

If visibility is obstructed during the day, only dipped beams may be used. High beams are never permitted during the day.

Article 1 of the Road Traffic Regulations (RVV).
Day: the period between sunrise and sunset.