Lesson video

Hello, my name's Mrs. Gulliver and I'm so happy that you are joining me for this lesson today, our final lesson on our unit time zones.

Can we time travel on planet Earth? Today's lesson is called Travel and Time, and by the end of the lesson, you'll be able to understand that time zones can have an effect on travel.

Now, some of this learning may be a bit new to you today, but that's okay.

I'll be here with you to help all along the way.

We've got three keywords for our learning today.

So I will say them first and then I will give you a turn to say them, my turn.

So the first word, or the first phrase I should say, Eastern Hemisphere.

Your turn.

Well done.

Western Hemisphere.

Your turn.

Great.

And last one, Daylight Saving Time.

Your turn.

Great job.

Now, we'll be finding out about these words as we go through the lesson, but let's just have a quick look at their meanings.

The Eastern Hemisphere is the half of the Earth that lies east between the prime meridian and the international date line.

The Western Hemisphere is the half of the Earth that lies west between the prime meridian and the international date line.

And daylight saving time is the practise of turning the time forward by one hour in spring to make use of longer daylight hours and turning time back to standard time in autumn when there are fewer hours of daylight.

Our lesson for today is gonna be split into two parts, so let's get going with our first part on, can we time travel? What an interesting question for us to find out about today.

Now, we've learned a lot about the prime meridian line through our previous lessons in this unit and we've learned that it runs through London in England and it marks nought degrees longitude.

It is also the boundary between two halves of the Earth.

Imagine cutting down through the prime meridian, you would end up with two halves of a sphere and these parts are known as hemispheres because hemi means half.

Everything to the west of the prime meridian is known as the Western Hemisphere and everything to the east of the prime meridian is called the Eastern Hemisphere.

In our last lesson, we also learned about an imaginary line called the antimeridian, which is also the basis for the international date line.

It acts as a boundary between one day and the next.

But we haven't talked yet about what happens if you cross the international date line.

International date line is on the opposite side of the world to the prime meridian, and the two hemispheres meet here at the antimeridian.

Do you think it's possible to travel through time if you cross the international date line? Let's find out.

Well, if you cross the international date line moving east, you must subtract a day from the date.

So Lucas says he could leave somewhere on the 3rd of January and travel east across the international date line so that when he arrives, it would be the 2nd of January again.

Well, that's amazing.

Not exactly going back in time, but it would be back in yesterday's date.

And on the other hand, if you cross the international date line moving west, you need to add a day.

And Izzy here says if she left somewhere on the 10th of July and travelled west across the international date line, then it would be the 11th of July when she landed, even if her journey time was only short.

And can you see from North America to Russia, there's a very small stretch of land.

It's actually only just over three kilometres.

Not very far at all.

If you travelled that short distance between the two places, if you were travelling from America to Russia, you would need to add a day.

I've got the first check for you today.

In which direction should you fly for today to become yesterday? So if you want to take back a day.

Lucas says, "I think you have to fly east across the international date line." Whereas Izzy says, "I think you have to fly west across the international date line." Have a think with your partner now and pause the video and we'll come back to check if you're right in a moment.

Well done.

I'm sure you said that Lucas was correct.

For today to become yesterday, you would have to fly east across the international date line.

This change in date can be represented using numbers.

If we move east across the international date line, we say that we need to take away one day.

We move back to the date before, one day before.

And if we travel west across the international date line, we say we need to add one day to the date that we are travelling into because we would've added one day to the date.

I've got another check for you.

If we travel from China to the USA one morning, what happens to the date when we land? And you can see here that China is the Western Hemisphere and the USA is in the Eastern Hemisphere.

So we would be travelling east, from west to east, so we would be travelling east.

So would that mean that we would need to add one day, it would be the same day, or we would need to take away one day? Have a think and pause the video.

So if we're travelling east from China to North America, did you say we would take away one day? We would be travelling back to the date one day before.

Well done.

For your first task today, I would like you to complete these sentences about travelling across the international date line.

When you travel west across the international date line to the Eastern Hemisphere, you hmm a day.

And when you travel east across the international date line to the Western Hemisphere, you hmm a day.

Pause the video now and have a go at those sentences.

I'm sure you had a good go at those.

Did you say when you travel west across the international date line to the Eastern Hemisphere, you gain a day.

And when you travel east across the international date line to the Western Hemisphere, you lose a day.

Great job.

Our second part of the lesson is going to be about what the time will be when we land.

Many flights cross time zones.

And this can make it difficult to work at the time when a plane lands at its destination.

If we imagine a plane is flying from Orlando to the United Kingdom, this could be difficult because we can see that that route would cross five time zones.

So when the plane landed in the United Kingdom, we would need to turn our watches forward five hours to adjust to the time in the United Kingdom.

Let's have a look at another example together.

Lucas is flying from Manchester to Rome and the flight takes three hours.

He departs at 8:00 a.

m.

and you can see that he is travelling east across the prime meridian line, which is shown there in red.

Lucas says, "My flight will land at 11:00 a.

m.

because eight plus those three hours will be 11:00 a.

m." Do you think that Lucas is correct? Have a think with the person next to you.

Well done.

Lucas was not correct because he has forgotten to adjust the time to match the destination because we can see on that map that the time zone he will be landing in in Rome is plus one hour UTC.

Italy is one hour ahead of time in the United Kingdom.

So Lucas needs to try again and he says, "My flight takes three hours, but the new time zone is plus one hour.

So the time when I land will be eight hours plus the three hours flying plus the one hour time zone difference that I need to adjust," so he will land at 12:00, so the local time on arrival in Rome will be 12:00.

Great job.

Now, unlike Italy, the United States of America is a huge country that is split into more than one time zone.

And therefore, we need to know the location of the airport that we're flying into to make sure we can adjust to the correct time.

How many time zones does the United States of America span? Have a think with the person next to you.

Well done, we can see that the United States of America spans six different time zones.

So those 50 states are split into six different time zones.

So finding the exact location of an airport is really important to know which time zone the location falls into.

I've got a check for you.

If a flight from London to Orlando takes nine hours and departs at 12 UTC, what time will it arrive in the United States of America? So we can see that the flight would be travelling west from the United Kingdom to the United States of America to Orlando, and you can see the different time zones there, and the flight takes nine hours, and remember to also adjust for the time zone difference.

Have a think, pause the video and we'll come back together in a moment.

Did you say it would be 4:00 p.

m.

in the afternoon? Because the flight would take nine hours, which would take us to 9:00 p.

m.

However, the time zone we are landing in in Orlando is five hours behind UTC, so we would need to take those five hours away, which would take us to 4:00 p.

m.

Great job.

Now to make matters even more complicated, some countries, including the United Kingdom, actually adjust their time in certain seasons to maximise the hours of daylight.

Daylight saving time is when the clocks are put forward by one hour near the start of summer.

This is so that daylight ends at a later time of the day.

It was first introduced because it was thought that by sleeping through daylight in summer, the day was being wasted.

So there are a number of countries which use daylight saving time.

In 2024, daylight saving time was observed in most of Europe, most of North America, and parts of Africa and Asia around the Northern Hemisphere summer.

And it was also used in parts of South America and Oceania around the Southern Hemisphere summer.

Interactive and digital time zone maps automatically take account of these time differences when showing the time at places around the world.

In the autumn when there are fewer hours of daylight, the time is turned back by one hour to standard time UTC.

This means that if the sunset had been at 4:00 p.

m.

, when the clocks go back, it would be sunset at 5:00 p.

m.

so it will not be quite as dark when you get home from school.

You might have heard the phrase "spring forwards and leap back" about how to change the times at the correct season.

This means we use UTC in winter and we use UTC plus one in summer.

Now, this does have an impact on time zones and can be extremely confusing.

I've got another check for you.

Why do countries use daylight saving time? I'm sure you had a good thing why countries use daylight saving time.

I wonder if your answer looks similar to mine.

Daylight saving time is used so that daylight ends at a later time of the day.

It was first introduced because it was thought that by sleeping through daylight in summer, the day was being wasted.

Great job.

Now our final task for today.

I would like you to use the internet or an atlas or a globe.

I would like you to choose an airport in the United Kingdom and then a destination that is to the east, west, north, or south.

Track the flight path and note any time zone changes and work out the arrival time.

Then I'd like you to repeat it for two other destinations.

So for example, I may choose Manchester Airport in the United Kingdom that departs at 8:00 a.

m.

I would then need to choose where my location is, where my destination's going to be.

I'd need to find out how long that flight takes, what time zone the destination is in, and then work out my arrival time.

Have a go at this task, pause the video, and I'll see how you've got on soon.

I chose to do my example flight from Edinburgh in the United Kingdom and I chose to fly all the way to the west coast of Canada to Vancouver.

So if I left Edinburgh at 8:00 a.

m.

in the morning and flew all the way to Vancouver, the flight time was 12 hours.

However, Vancouver is in the time zone that is minus eight hours from UTC.

So although I left at 8:00 and flew for 12 hours, we'd actually land in Vancouver at midday, only four hours later.

Let's summarise our learning today about travel and time.

Many flights cross time zones leading to discrepancies between the time in the air and the time at destination airports.

Some flights cross the international date line moving between the western and Eastern Hemispheres of the globe.

Some countries, including the United Kingdom, adjust their time in certain seasons to maximise their hours of daylight.

Interactive flight maps can be used to investigate the complex pattern of international flights.

So in summary, although we cannot travel through time, humans have managed to adjust time to maximise the hours of sunlight they receive.

And because of this, we do need to make adjustments to the time and date when we travel.

I hope you've enjoyed finding out about travel and time as much as I have.

Thank you so much for joining me.

I hope to see you again soon.

Bye.