In this video, we are going to use the Geography Visualizer, which is a geographic information system to look at different time zones around the world. Now a few basic things about the Geography Visualizer in case you've not used it before. First thing is you may need to move the map around. So to do this on my mouse, I can hold the left button of the mouse around and then drag the map to a different part. Call this panning, so you can see now the India is in the center of the screen and I can again click on the left side of the mouse and drag back so the UK is roughly in the center. The other thing that's really important to be able to do is to zoom in and out because we might need to investigate at a more local scale. So I can use the scroll wheel of my mouse to do this. So there's zooming in and zooming out. But I can also on the left hand side, use these zoom out and zoom in buttons. And that allows me to zoom in so we can look at the world at different scales. Now, at the moment, we have a satellite image of the world, but we've also got the borders of the countries on the map. So we call this an imagery hybrid map. And this is a type of base map. And a base map is a background map or satellite image. And you can see at this bottom toolbar it says base maps. And if I want to change the base map, I can click on this and I can choose from lots of different background maps, different base maps, but I don't want to do that right now. What I would like to do is I would like to add some data onto this map and I would like to add the data or information about the different time zones of the world. Now we call this a layer of data, and there's two places in the Geography Visualizer that I can find layers of data. I can click on this add layer and there is lots of different options for me to choose, or I can choose on this open map in this bottom toolbar. And that will give me lots of different maps that have already been curated with a data layer on. In this video, I need to use this open map button. So I'm going to click on this, my left button. And you can see lots of different maps, different layers of data that have now appeared. If I scroll down, I'm using the scroll wheel of my mouse, but I could use this handle, I can come to the bottom and you can see there's lots of different layers. You can see there's a layer showing the cities around the world, for example, here. But we need this layer where it says time zones. So if I click on this, there's a number of things that happen. First of all, you'll see there's lots of yellow lines on the map and they are the time zones of the world and we'll look at those in a second. But the other thing you'll notice is the base map is no longer a satellite image. It's actually a kind of white map with the countries on. Now, the reason it's changed that is it's much easier to be able to see the time zones if it's on a white background. So rather than change the base map back to a satellite image, I would just keep it as it is 'cause they're much easier to see this way. So we can see these yellowish lines running down the map now, and this is showing the time zones around the world, but at the moment it's difficult to know what they mean. So what I'm going to do is I'm going to drag the UK in the middle. I'll zoom in a little bit and I'm going to click on an area just somewhere within the UK. And you'll notice that this whole area, which is all of the time zone, has been highlighted in turquoise. And it doesn't matter if I zoom out or zoom in, it's still going to be highlighted in this sort of turquoise color. And we can see it says zero. The local time here can be calculated by adding or subtracting zero hours to the Greenwich mean time and the Greenwich mean time is the time we have in the UK. Greenwich is in London, and it is a time that is used internationally to work out what the time is around the world. But that means that we don't really need to do anything to Greenwich meantime 'cause it's the time that we use. But if I choose a different place, let's say I click on Finland here, you'll notice that all of a sudden we've got a different area which has been highlighted, and then it says two, the local time here can be calculated by adding or subtracting two hours to Greenwich meantime. So that means if I want to know what the time is in Finland, I need to know what the time is in the UK. So let's say it's one o'clock in the afternoon in the UK and I can add two hours to this to know what the time is in Finland. So two hours onto one in the afternoon would make it three in the afternoon in Finland, 3:00 PM. So that's what's happening if we're going towards the east of the UK, what happens, let's say if I click on Greenland here, you'll see that now this area of land is highlighted and you can see that it says minus three. So the local time can be calculated by adding or subtracting minus three hours to Greenwich mean time So that means that if it's one in the afternoon in the UK, then it's going to be 10 in the morning, 10:00 AM in Greenland and in wherever is highlighted on this area. So the east of Brazil, for example, will be the same, also into Argentina. So there's a few things to note about this map. Generally, the time zones run from north to south, kind of down lines of longitude around the world. But it's not perfect, is it? 'Cause it kind of takes into account country boundaries. We have some countries, let's say the United States, whereas if you look at it, there is different time zones across the country. So depending on where you were in the United States, depends upon the time. So countries aren't always in the same time zone, especially if they're really wide across the world. So they stretch really far from east to west. Now there are some exceptions. There are some countries that you may be able to find where you would expect there to be different time zones, but there's actually not.