List II, the places that normally keep UTC — Page 422, Lesson 374

We're moving into the second part of the Time chapter now, and this is where we get very practical. We've dealt with the theory of time, and now we're looking at the real-world application: standard times. This is the list of places that keep Coordinated Universal Time, or UTC, and then a list of places that are slow on UTC, meaning they're west of Greenwich. Let's start with List II, the places that normally keep UTC. UTC is the primary time standard, the modern successor to Greenwich Mean Time. If a place keeps UTC, its local standard time is exactly the same as UTC. So, if it's 1200 UTC, it's 1200 local time there. Looking at the list, we have places like Ascension Island, Ghana, the Irish Republic, Morocco, Sierra Leone, and Great Britain. Notice the footnote markers. The asterisk, *, means summer time may be kept in these countries. So, for example, the Irish Republic and Portugal have that asterisk, meaning they may shift their clocks forward during summer months. Now, there's a specific footnote for Great Britain, the Channel Islands, and Northern Ireland, marked with a superscript 1. It says summer time, one hour in advance of UTC, is kept from March 25d01h to October 28d01h UTC, subject to confirmation. So, for these places, during that period, their local time is UTC plus one hour. That's British Summer Time. The notation "25d01h" means the 25th day at 01 hours, so the change happens at 0100 UTC on those dates. Let's continue with the rest of List II. We have Bourkina-Faso, the Canary Islands, the Channel Islands, the Faeroes, Gambia, Guinea Bissau, Guinea Republic, Iceland, Ivory Coast, Liberia, Madeira, Mali, Mauritania, Principe, Sao Tome, Senegal, St. Helena, Togo Republic, and Tristan da Cunha. Many of these are island territories or West African nations. The key point is that for all of them, their standard time is UTC. No offset, no adjustment. Now, let's move to List III, which is the big one: places slow on UT, or west of Greenwich. The heading explains the relationship clearly. It says the times given should be subtracted from UTC to give Standard Time. And then it clarifies: the times below should be added to Standard Time to give UTC. So, if a place is listed with a value of 05, that means its standard time is UTC minus 5 hours. To get from local standard time back to UTC, you add 5 hours. Let's look at some examples. Argentina is listed with 03. So, Argentina's standard time is UTC minus 3 hours. The Cape Verde Islands are 01, so UTC minus 1 hour. The Azores are also 01. Now, look at Newfoundland. It's listed as 03 30. That's a half-hour offset. Newfoundland is UTC minus 3 hours and 30 minutes. This is a classic example of a non-whole-hour offset, and it's crucial for flight planning. You can't just assume every time zone is a whole number of hours. Now, let's look at Canada, which is broken down by province and even by longitude within a province. For example, Alberta is 07, British Columbia is 08, and Manitoba is 06. But look at Ontario. It says "east of long. W.90°" is 05, and "west of long. W.90°" is 06. So, the province of Ontario is split by the 90th meridian west. East of that line, they're UTC minus 5; west of it, they're UTC minus 6. This is the kind of detail you need to be aware of when you're crossing provincial or state boundaries. Similarly, look at Quebec. East of longitude W.63° is 04, and west of W.63° is 05. And Saskatchewan is split too: east of W.106° is 06, and west of W.106° is 07. The Northwest Territories are also divided into multiple zones based on longitude. This shows that time zones are not always simple political boundaries; they can be defined by lines of longitude. Now, let's look at the footnotes for List III. The asterisk again means summer time may be kept. So, for example, the Bahamas, Bermuda, Chile, and Cuba all have asterisks. There's a footnote 1 for the Austral Islands, which says "This is the legal standard time, but local mean time is generally used." So, even though the legal standard is UTC minus 10, in practice, they use local mean time. That's an important distinction. Footnote 2 applies to Brazil, eastern. It says "Including all the coast and Brasilia." So, when you see Brazil, eastern at 03, that includes the entire coastline and the capital city, Brasilia. Footnote 3 is for the British Antarctic Territory, and it says "Except South Georgia which keeps 02h." So, the main territory is UTC minus 3, but South Georgia is UTC minus 2. Footnote 4 is for Greenland, specifically Danmarkshaven, which keeps UT, meaning UTC, even though the rest of Greenland is on various offsets. Let me also point out a few more entries. The Falkland Islands are 04, Easter Island is 06, and the Galapagos Islands are 06. The Cook Islands are 10, and Johnston Island is 10. These are all in the Pacific, far west of Greenwich, so they're many hours behind UTC. So, the core concept here is the relationship: Standard Time equals UTC minus the listed value. And to convert back, you add the value to Standard Time to get UTC. This is fundamental for any navigation calculation. When you're given a local time at a place, you need to know its offset from UTC to convert it to UTC for your flight planning. And when you're given a UTC time, you need to know the offset to figure out the local time at your destination. Let's look at the figures available. There's a figure showing LMT and UTC, and another showing the International Date Line. These are useful visual references, but the key takeaway from this excerpt is the practical application of these time offsets. So, to summarize what we've covered: List II gives us places where standard time is exactly UTC. List III gives us places where standard time is behind UTC, and the number tells us how many hours and minutes to subtract. The asterisks and numbered footnotes give us crucial exceptions and clarifications, like summer time, legal versus local time, and specific regional variations. This is the data you'll be using to solve time problems in navigation.