Which is the most correct approach to fasting Ramadan in a country where the day extends to nearly 21 hours in summer and shortens in winter?

Fasting is obligatory for anyone who is in a country where there is both night and day within a twenty-four-hour period, whether the day is long or short, due to the generality of Allah Almighty's saying: "And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the night." And whoever is unable to continue fasting due to an excuse, such as illness, may break their fast and must make up the days they missed at a time when fasting is easy for them.