The length of the race must be 305 km 260 km in case of Monaco GP and is defined as the smallest number of complete laps that exceeds 305 kilometers. The 2019 regulations state that the drivers have 45 minutes to complete the race once the 45 minutes is up they have to complete one extra race. Full list of countries and channels that broadcast Formula 1 around the world.
3780 km 2349 mi Australian Grand Prix.
No there is not any limit for a track lap distance although the FIA recommends a maximum lap length of 7Km in its procedures for the approval of new F1 circuits but in any case one single strait section can not exceed 2Km. That is probably why we only have one true night race in Formula 1. Unlike in most other motorsport series there is not a set number of laps. 7618 km 4734 mi Moroccan Grand Prix.