This kind of thing is one of my pet peeves.<p>The author is not doing math about how many Fridays are in February at all. The calendar does not change based on your physical movements. The author is actually answering the question "how many Fridays is it possible for you to experience in a month", not "how many Fridays are in a month".<p>Those are two entirely different things.<p>If you are traveling fast enough to experience increased daylight because you are staying on the lit side of the globe for longer, it's not correct to say you've increased the number of daylight hours in a day in some kind of objective way. You've only increased the number of daylight hours you've experienced.