What Time Is It In Tokyo? (1971)

Morning friends in North America. This is Bumpei Kahunahuna speaking to you from Tokyo, Japan. It's a beautiful day here and we are glad because this is a special day for you and for us. This program is being relayed by satellite so that what you see on your TV is actually happening this very moment. It's miles away from you in the United States and 10:00 in the morning here, but we have a reason for starting this special touching early time. 10th, the first day of school for many Japanese children. They're meeting their teacher for the first and some of them seems to be a little nervous. But they're ready. >> They're watching these children who are going to school at 8:00 in the morning on Monday. Are you wondering why there is such a difference in time? >> [music] [bell] >> Before there were clocks, early man lived by the sun. He went to bed when the sun went down and he got up when the sun came up. He could tell when it was midday because the sun was at the highest point in the sky. So he learned to keep time by the sun. It was agreed to divide the day into 24 equal parts and to call these parts hours. Men tried several different ways of keeping track of the hours. The best device was something called a clock. And as men traveled to different parts of the world, the idea spread. Navigators and astronomers especially liked the idea. And people all over the world adopted the clock as the best way to keep track of the time of day. Even though today man lives by the clock, that habit of living by the sun is a hard one to break. So, now everyone around the world sets the time on their clocks according to where the sun is for them. This is the reason why we have different times around the world. We know that the Earth rotates 360° once every 24 hours. It rotates on its axis from west to east. At this moment for the people on the dark side of the Earth, it's night time. And for the others, it's day time. It's sunset now for some of the people in North America, late in the afternoon. But, it's the start of a new day in Tokyo, early in the morning. If everyone set his clock exactly by the sun, then clocks all around the world would be a little bit different. It takes 24 hours for the Earth to rotate. So, there are 24 hours in the day. Since the Earth rotates 360° in this 24 hours, let's divide the world into 24 equal sections by drawing lines from the North Pole to the South Pole. We'll call these sections time zones. Each time zone will be 15° of longitude. Each section, or time zone, will have its own official clock set by the sun. >> Yes, it's 8:00 in Tokyo, where today some of these children will be going to school for the first time in their lives. We want to visit with them for a while, so you'll better understand what life is like for Japanese children. >> [music] [screaming] [music] [music] >> If you were to fly to Japan from your hometown, you would probably take a jet plane. Why don't we plan a trip and find out the interesting things that happen to time on the way? >> [music] [music] >> We'll start in Montreal, [music] Canada, and we want to fly west to Tokyo, Japan. Our flight is going to make several stops. We'll stop for [music] passengers in Chicago. We'll also stop in Denver. >> [music] >> And we'll stop in San Francisco. Now, let's think about what happens to time on this trip. >> [music] >> If it's 4:00 in the afternoon when we leave Montreal, what time is it in each of the other cities? It's 3:00 in Chicago. It's 2:00 in Denver. And it's 1:00 [music] in San Francisco. Montreal, Chicago, Denver, San Francisco. Each city is 1 hour apart because each city is in a different time zone. What are you going to do about the difference in time? You're going to set your watch back 1 hour for each time zone you enter as you travel west. But what will happen to the length of your day? Will it be longer or shorter? Since you [music] set your watch back, your day will be 3 hours longer going to San Francisco. And 10 [music] hours longer going to Tokyo. Why will it be longer? >> [music] >> Because when you travel from east to west, you are traveling in the same direction as the sun appears to be moving across the sky. And you will have the sun in sight [music] longer. Actually, as you travel [music] west in a fast jet plane, you are traveling in the opposite direction to the Earth's rotation. This has [music] the effect of keeping the sun in sight longer and thus lengthens your day. But, we've been traveling west all this time. What happens when you travel east in the opposite direction? Just the opposite happens. The days will be shorter. Why? Because you set your watch 1 hour ahead for each time zone you enter. Now, this creates a real problem on the calendar. Remember when we were watching the television program from Japan? It was Sunday, September 14th where we were and at the same time, it was Monday, September 15th in Japan. Let's suppose you and a friend decide to take a trip to Tokyo and you want to go around the world in opposite directions. You're both going to travel by rocket because it's the fastest way to go. You are going to steer your rocket east over the Atlantic Ocean and your friend will steer his rocket west over the Pacific Ocean. It's Sunday, September 14th. >> 5 4 3 5 3 2 1 0 >> [music] [music] [music] >> When you both arrive in Tokyo, the local time is 8:00 a.m. Your clock went past midnight, so your calendar date changed to Monday, September 15th. Your clocks would be the same, but your calendars would show a different date. In order to keep this from happening, we've put a line on our maps and globes running from north to south through the Pacific Ocean called the International Date Line. It's at 180° of longitude, which is called the 180th meridian. If you cross this line going west, you jump ahead one day on the calendar. And if you cross this line traveling east, you jump back one day. When your friend flying west crosses the International Date Line, he jumps ahead one day, and both of you arrive on the same day and date. Perhaps now you're thinking it would be much easier if people all over the world would set their clocks the same. If we did this, we wouldn't need time zones, and we wouldn't need an International Date Line. When it's 8:00 a.m. in one part of the world, it would be 8:00 a.m. every place in the world. But if you took a trip to a place such as Tokyo, 8:00 a.m. might be the time you woke up in the morning, but 8:00 a.m. Tokyo time would be late at night for the Japanese people. So, to keep things orderly, maybe we'd better continue to depend on the sun as a guide in how to set our clocks. Perhaps we should keep the time zones and the international date line. And when we cross the date line going west, we'll just have to remember to jump ahead one day on the calendar. >> [music] >> This happens even if you do your traveling by television. Because right now for these children, it's 9:00 at night on Sunday, September 14th. And at the same time in Japan, it's 12:00 noon on Monday, September 15th. And time for lunch. >> We have paused for a few moments in our busy schedule for the children to have lunch. Ah, so. This is sushi. They especially enjoy this. It is made from rice and vegetables. Sometimes seaweed is used. >> Yes, that habit of living by the sun is a pretty hard one to break. >> [music]