You'll see the days numbered — 19, 22, 25, 28, then 1, 4, 7, 10, 13, 16, 19… — Page 455, Lesson 448

I want to walk you through the sunrise table — this is the kind of data you'll actually use in flight planning, so let's make sure you can read it properly. First, the title: this is a table of sunrise times, and it's laid out by latitude and by date. The latitudes run down the left-hand side, from N72 at the top all the way down to S20 at the bottom. The dates run across the top, starting in November and going through December into January. You'll see the days numbered — 19, 22, 25, 28, then 1, 4, 7, 10, 13, 16, 19, 22, 25, 28, 31, then 3. So the columns cover roughly mid-November to early January. Now, the times themselves are given in hours and minutes — that's what the "h" and "m" at the top of the columns mean. So when you see something like "10 14", that's 10 hours and 14 minutes. These are local times of sunrise at that latitude on that date. Let me show you how to read one entry. Look at latitude N70, in the November column for the 19th. You'll see "10 14" — so at 70 degrees north, on November 19th, the sun rises at 10:14. Move across to the next column, the 22nd, and it's 10:40. Then the 25th, 11:19. Notice what's happening — as we go deeper into winter, sunrise is getting later. That's the key pattern in this table. Now look at the top of the table, at N72. You'll see the cells are blank — there are no times at all. That's because at 72 degrees north in late November and December, the sun doesn't rise at all. That's polar night — the sun stays below the horizon. The table leaves those cells empty because there's no sunrise to record. Let's trace a full row to see the trend. Take N60, the row that starts "08 07". On November 19th, sunrise is at 08:07. It gets later and later through December — 08:45, 08:50, 08:54, 08:58, then 09:00, 09:02, 09:03. It peaks around 09:03 in late December, then starts coming back earlier — 09:01, then back down. So the latest sunrise happens around the winter solstice, and then the trend reverses. Now compare different latitudes on the same date. On November 19th, at N60 sunrise is 08:07, but at N50 it's 07:18, and at N20 it's 06:11. The further north you go, the later the sunrise in winter — and the further south, the earlier. At the equator, the 0-degree row, sunrise is around 05:44 to 06:01 — it stays fairly constant because day length doesn't change much at the equator. Look at the southern latitudes — S10 and S20. At S20, on November 19th, sunrise is at 05:12. Notice the times there are getting earlier as December approaches — 05:11, 05:12, 05:12 — because it's summer in the southern hemisphere. The sun rises earlier as you go south in November and December, the opposite of the northern hemisphere. One more thing to notice: the times are not perfectly smooth. Look at N64 — 08:39, 08:48, 08:57, 09:06 — it's climbing steadily, then 09:15, 09:23, 09:30, 09:36, 09:42, 09:47, 09:50, 09:52, 09:53, then it holds at 09:52, 09:51, 09:48. So it rises to a peak around late December and then starts falling. That's the solstice effect again. So when you use this table in practice, you pick your latitude, pick your date, and read off the local sunrise time. If you're planning a flight that departs before sunrise, you need to know when the sun comes up — and this table gives you that, for any latitude from N72 down to S20, across the November-to-January period. That's the whole table