Insights&
Aviation Tips

How Night Time Is Actually Calculated (And Why “Sunset + 30 Minutes” Is Wrong)

If you ask pilots how they log night time, many will say the same thing: start 30 minutes after sunset, stop 30 minutes before sunrise. It’s easy to remember, easy to teach, and widely used in flight schools. The trouble is that no major aviation regulator defines night that way. It’s a rule of thumb—not a legal definition. For logbook totals, currency, and ratings, what matters is civil twilight, and that changes with latitude, season, and where you are along your route. This article explains what “night” really means for logbook purposes, why shortcuts break down, and how accurate night time is calculated on cross-country flights—including what tools like the Pilotflows Night Time Calculator do under the hood.