The column on the far left is labelled Lat — Page 447, Lesson 422

This is a sunrise/sunset table — the kind of page you’ll find in the back of your navigation manual, and it’s one of those pages that looks like a wall of numbers until you know exactly how to read it. Let me walk you through it properly, because this is a real working tool for planning. First, what this table actually gives you: the time of sunset at various latitudes throughout the year. The column on the far left is labelled Lat. — latitude, in degrees north, running from N 72 down to N 52. So this particular table covers high northern latitudes, from 72°N down to 52°N. The rows across the top are the months — May, June, July — and within each month, the columns are individual days: 17, 20, 23, 26, 29, then 1, 4, 7, 10, 13, 16, 19, 22, 25, 28. So you read it as: pick your latitude, pick your month and day, and the number in the cell is the time of sunset. Now, the times are given in hours and minutes — the header shows h and m for hours and minutes. And here’s the critical part: these are UTC times, not local times. That’s the whole point of a table like this in navigation — you work in UTC so you can compare with your flight plan, your fuel calculations, and your other navigation data without worrying about time zones. Let me show you how to read one entry. Take latitude N 60. On May 20, the table gives 20 49 — that’s 20 hours 49 minutes UTC. So at 60° north on the 20th of May, the sun sets at 20:49 UTC. Now look at the same latitude later in the year — July 28 at N 60 gives 21 25. So you can see the sun setting later in July than in May at the same latitude. That’s the seasonal shift. Now, here’s something you’ll notice immediately: some cells contain the letter G instead of a time. Look at the high latitudes — N 72, N 70, N 68 — for most of May, June, and July, the entry is just G. That stands for continuous daylight — the sun never sets at all. At those latitudes in summer, you get the midnight sun, so there is no sunset time to record. That’s why the table gives you a letter instead of a number. So if you’re planning a flight at 70° north in June, you don’t need to worry about sunset for lighting or night operations — it simply doesn’t happen. Let me trace one latitude all the way through to show you the pattern. Take N 66. On May 17 it’s 21 40. Then it climbs: May 20 is 21 52, May 23 is 22 05, and it keeps rising through 22 18, 22 31, 22 45, 22 59, 23 15, 23 33 — and then on June 28 it hits 23 44, the latest sunset of the year at that latitude. Then it starts coming back down. So you can see the sun setting later and later through late May and June, peaking around the summer solstice, then reversing. Now here’s a subtle thing I want you to notice, because it’s easy to misread. Look at the N 56 row. On May 20 it reads 20 09, then May 23 is 20 15, May 26 is 20 20 — wait, let me re-read that carefully. The entry for May 26 at N 56 is 20 20, then May 29 is 20 25, then June 1 is 20 29, and it climbs to 20 34, 20 38, 20 41, 20 44, 20 46, 20 48, 20 50 — and then it holds at 20 50 for a few days before starting to decline. That plateau is the peak around the solstice. So the pattern is: a steady climb, a flat peak, then a steady decline. One more thing to check — the N 54 row. May 17 is 19 59, then 20 04, 20 08, 20 13, 20 17, 20 21, 20 24, 20 27, 20 30, 20 32, 20 34, 20 35, 20 36 — and again it holds at 20 36 for a few days, then drops back to 20 35. So the same shape, just earlier times because you’re at a lower latitude. So the key takeaways for you as a pilot: this table gives sunset time in UTC for a given latitude and date across May, June, and July; the G entries mean continuous daylight — no sunset; and the times climb to a peak around the summer solstice and then fall back. When you’re planning night operations or calculating when you’ll need lighting, this is the page you’d pull up.