Let me read one row properly so you can see the pattern — Page 453, Lesson 442

Let’s start with what this page actually is, because it looks like a wall of numbers and it’s easy to get lost. This is a sunrise table — a tabulated set of times of sunrise, given in hours and minutes, for a range of latitudes and for each day of the year, arranged by month. The page is headed “Time (3)” and it’s part of the general navigation material, so the whole point is that you, as a pilot, can look up when the sun will rise at a given latitude on a given date without having to compute it from scratch. The table is organised with latitude down the left-hand side, from N72 at the top, through N70, N68, N66, N64, N62, N60, N58, N56, N54, N52, N50, N40, N30, N20, N10, then the Equator marked as 0, and then into the southern hemisphere with S10, S20, and S30 at the bottom. So the rows are latitudes, and the columns are dates — the months run across the top, starting with October and then November, and within each month the days are numbered 2, 5, 8, 11, 14, 17, 20, 23, 26, 29, then 1, 4, 7, 10, 13, 16, 19, and so on. So each column is a specific day, and each cell is the time of sunrise at that latitude on that day. Let me read one row properly so you can see the pattern. Take N60. On October 2nd, sunrise is at 06 07 — that’s 06 hours 07 minutes. On October 5th it’s 06 14. October 8th, 06 21. October 11th, 06 28. October 14th, 06 36. October 17th, 06 43. October 20th, 06 50. October 23rd, 06 58. October 26th, 07 06. October 29th, 07 13. Then November 1st, 07 21. November 4th, 07 29. November 7th, 07 36. November 10th, 07 44. November 13th, 07 52. November 16th, 07 59. November 19th, 08 07. So you can see the sun is rising later and later as autumn progresses — the times are getting later by roughly 7 or 8 minutes every three days at this latitude. Now compare that with a lower latitude. Look at N20. October 2nd is 05 51, October 5th is 05 52, October 8th is 05 52, October 11th is 05 53, October 14th is 05 54, October 17th is 05 55, October 20th is 05 56, October 23rd is 05 57, October 26th is 05 59, October 29th is 06 00, November 1st is 06 01, November 4th is 06 03, November 7th is 06 04, November 10th is 06 06, November 13th is 06 07, November 16th is 06 09, November 19th is 06 11. So at N20 the change is much smaller — only a few minutes across the whole period, because near the Equator the length of day barely varies through the year. That contrast is the key lesson of this table. The higher the latitude, the more rapidly sunrise times change from day to day, and the greater the seasonal swing. At N72, the top row, the times are much later — October 2nd is 06 21, and by November 19th it’s 10 27. That’s a huge shift, over four hours, because at high latitude in late autumn the sun is climbing much later each day as winter approaches. Now look at the southern hemisphere rows. At S10, the values are in the 40s and 50s — for example, the row starts with 46, 45, 44, 44, 43, 42, 42, 41, 41, 40, 40, 40, 40, 40, 41, 41, 42. These are minutes, and the pattern is the opposite of the north — the times are getting earlier as we go through October and November, because in the southern hemisphere it’s spring, heading toward summer, so the sun is rising earlier each day. At S30, the bottom row, you can see values like 05 38, then 05 34, 05 31, 05 27, 05 24, 05 20, 05 17, 05 14, 05 11, 05 08, 05 0… — the times are clearly decreasing, sunrise getting earlier as the southern summer approaches. So the whole table is a lookup tool: you enter with your latitude and your date, and you read out the time of sunrise in hours and minutes. The times are given in UTC — that’s the standard convention for these tables, so you’d then apply your longitude correction and any time-zone offset to get local time, but that conversion is handled elsewhere in the chapter. What this page gives you is the raw sunrise time as a function of latitude and date. One more thing to notice: the table only covers October and November here, and the latitudes run from N72 down to S30. That’s the range and the period this particular page covers. The structure is the same for every month and every latitude band in the full set — you just pick the right page, the right row for your latitude, and the right column for your date. So the takeaway for you as a navigator: sunrise time is not a constant — it depends on two things, your latitude and the date. High latitude means big daily changes; low latitude means small changes. Southern hemisphere rows run the opposite trend to northern rows because the seasons are reversed. And the table gives you the answer directly in hours and minutes, ready to use.