The International Date Line, Explained

Summary

This video script explores the complexities of the International Date Line, a concept that can be puzzling and inconsistent across different maps. The host dives into the history and purpose of the line, explaining how it affects time zones and dates, and why it zigzags to accommodate geopolitical decisions. The script also discusses discrepancies between various sources like Google Maps and PacIOOS, revealing that Google Maps incorrectly places certain islands on the wrong side of the Date Line. The video concludes with a reflection on the flexibility of the Date Line and its significance as a preference rather than a rigid border.

Takeaways

• 🗓️ The International Date Line (IDL) is not a fixed border but a conceptual line that divides the Earth into different calendar days.
• 🌏 Traveling across the IDL can cause you to 'jump' forward or backward in time, depending on the direction of travel.
• 🕊️ The IDL is not consistent across all maps due to varying interpretations and adjustments for political and practical reasons.
• 📊 Different sources, such as Google Maps and PacIOOS, may show the IDL in slightly different ways, reflecting the flexibility of the line.
• 🏝️ The IDL zigzags to accommodate the time zone preferences of various countries and territories, such as Russia, Alaska, and Kiribati.
• 🌅 The concept of the IDL can be confusing, as it involves the idea of crossing a line and experiencing a different day without significant travel.
• 🌍 The IDL essentially divides the Earth into 'Monday' and 'Tuesday' sides, based on whether it's late on Monday or early on Tuesday in a given location.
• 📡 The Pacific Island Ocean Observing System (PacIOOS) is one of the sources that provides data on the IDL, which can differ from other sources like Google Maps.
• 🛳️ Traveling south by boat can also result in experiencing an earlier day, as demonstrated by the example of watching a Monday sunset after leaving on a Tuesday.
• 🔄 The IDL has changed over time as countries have made unilateral decisions about their preferred time zones and calendar days.
• 🌴 The IDL passes through some of the most beautiful and remote parts of the world, including the Pacific Ocean and its many islands.

Q & A

What is the International Date Line and why does it zigzag?

The International Date Line is an imaginary line that roughly follows the 180° meridian, which separates the Earth into the Eastern and Western Hemispheres. It zigzags to accommodate political and geographical considerations, ensuring that entire countries or territories are not divided into different days.

Why does the International Date Line start following the 180th Meridian and then split off?

The line splits off to avoid dividing certain territories, such as the Russian island and the eastern tip of Russia, into different days, thus ensuring they all belong to the same date.

What is the significance of the 'notch' in the International Date Line?

The 'notch' accommodates the island nation of Kiribati, allowing it to be on the Eastern Hemisphere time zone with Australia and Asia, and ensuring that other nations like the Cook Islands are on the Western part, aligning with the United States.

Why does the International Date Line have different representations on various maps?

Different maps may show variations in the International Date Line due to the flexibility of the line and the unilateral decisions made by countries regarding their time zones and dates.

How can crossing the International Date Line cause you to jump from Monday to Wednesday in a flight?

When flying from Hawaii to New Zealand, if you cross the International Date Line in such a way that you move from a later date to an earlier one and then back again, you can end up on a different day of the week due to the time differences and the direction of the line's zigzag.

What is the difference between the International Date Line and a regular border?

A regular border denotes the sovereignty of a country, dividing land and resources. The International Date Line, however, is a conceptual line that indicates the preference of countries on how they want to measure their time and does not denote ownership of land or resources.

Why might a country decide to change its position relative to the International Date Line?

A country might decide to change its position relative to the International Date Line to align its time zone with major trading partners or for convenience in communication and business operations.

How does the International Date Line affect the time zones of islands close to the line?

Islands close to the International Date Line may be on different sides of the line, resulting in different time zones and dates. For example, the islands of Samoa and American Samoa are on opposite sides of the line, with Samoa being one day ahead.

What is the role of a VPN in accessing content that is not available in a user's country?

A VPN (Virtual Private Network) allows users to encrypt their internet connection and route it through a server in a different country, enabling them to access content that is region-locked or restricted to other countries.

How does the script's author feel about discovering that Google Maps might have an error in its representation of the International Date Line?

The author expresses surprise and a slight existential crisis upon discovering the potential error in Google Maps, as they have a deep appreciation for the mapping service. They invite others to point out any flaws in their analysis.

Outlines

00:00

🌐 Understanding the International Date Line

The script introduces the concept of the International Date Line, a geopolitical construct that can be confusing due to its irregularities and variations across different maps. The narrator begins by expressing their intent to explore the Date Line's intricacies, starting with a personal anecdote about a promise to make a video on the subject. They delve into the complexities of time zones, particularly the peculiar experience of crossing the Date Line while traveling, which can result in jumping days. The narrator also mentions the discrepancies in how the Date Line is represented, from Google Maps to the CIA World Factbook and PacIOOS, highlighting the variations in mapping and the lack of consensus on its exact path.

05:02

🗺️ The International Date Line's Twists and Turns

This paragraph delves into the geographical and political reasons behind the International Date Line's unconventional shape. The narrator explains the Date Line's purpose as a conceptual division that determines the start and end of days across the globe, contrasting it with traditional borders that denote land ownership. They describe how the line deviates from the 180th Meridian to accommodate political and territorial considerations, such as avoiding splitting Russian islands and ensuring certain Alaskan islands belong to the same time zone as the U.S. The paragraph also touches on how different countries can choose their own relation to the Date Line, affecting its position and the time zones of islands in the Pacific.

10:04

🕰️ The Fluidity and Flexibility of the Date Line

The narrator discusses the fluid nature of the International Date Line, emphasizing that it is not a fixed or agreed-upon border but rather a matter of national preference. They provide historical examples, such as Samoa's decision to switch sides of the Date Line to align more closely with Australia and New Zealand's time zones. The paragraph also addresses the discrepancies between different map sources, particularly the difference between Google Maps and PacIOOS, concluding that Google Maps has inaccuracies in its representation of certain islands' time zones. The narrator invites viewers to challenge their findings, expressing a desire to be proven wrong and highlighting the subjective nature of the Date Line.

15:05

🌍 Sponsor Spotlight: ExpressVPN for Global Access

In the final paragraph, the script shifts focus to a sponsorship message for ExpressVPN, a Virtual Private Network service. The narrator explains the utility of a VPN in securing internet connections and accessing geo-restricted content, such as different Netflix libraries. They share their personal experience with the product and offer a promotional link for viewers to take advantage of a special offer. The paragraph serves as a transition from the educational content to a practical application of the concepts discussed, emphasizing the VPN's ability to navigate the complexities of global digital access.

Keywords

💡International Date Line

The International Date Line is an imaginary line of demarcation on Earth that separates one calendar day from the next. It roughly follows the 180-degree longitude line but deviates to pass around some territories and island groups. In the video, the concept is explored to explain why crossing this line can result in jumping a day forward or backward, which is central to the video's theme of understanding time and geographical anomalies.

💡Time Zones

Time zones are regions of the Earth that observe the same standard time due to being at a similar longitudinal position relative to the Prime Meridian. The video script discusses how time is measured from the Prime Meridian in Greenwich, and how the International Date Line interacts with time zones, especially in the context of the Pacific Ocean and its islands.

💡Greenwich Mean Time (GMT)

Greenwich Mean Time is the mean solar time at the Royal Observatory in Greenwich, London, which has been used as the international reference time. In the script, GMT is used as a reference point to explain how time progresses around the world and how the International Date Line affects the local time relative to this standard.

💡Zigzagging

The term 'zigzagging' in the script refers to the irregular path of the International Date Line as it deviates from the 180th meridian to accommodate political and geographical considerations. This term is used to describe the line's physical appearance on the map, emphasizing its non-linear nature.

💡Hemispheres

The Earth is divided into the Eastern and Western Hemispheres based on the Prime Meridian and the International Date Line. In the video, the concept of hemispheres is used to explain why certain islands or territories might choose to align with one hemisphere's time zone over the other, affecting their position relative to the Date Line.

💡Kiribati

Kiribati is an island nation in the Pacific Ocean that is mentioned in the script as an example of a country that has made a unilateral decision regarding its position relative to the International Date Line. The decision was made to ensure the entire nation is on the same calendar day, which is a practical illustration of how countries can influence their relation to the Date Line.

💡Samoa

Samoa is highlighted in the script as an example of a country that has moved itself from one side of the International Date Line to the other to align its time zone with its Pacific neighbors, such as Australia and New Zealand. This move is a practical example of how the Date Line's position can change based on a country's preference.

💡Alaska

Alaska is mentioned in the script to illustrate the geographical anomalies created by the International Date Line. A specific example is the case of two islands near Alaska, where one island is in the 'Tuesday' side of the Date Line and the other in the 'Monday' side, despite their proximity.

💡VPN (Virtual Private Network)

While not central to the main theme of the video, VPN is mentioned as a tool for accessing region-locked content on platforms like Netflix by changing the apparent geographical location of the user. The script uses ExpressVPN as an example to demonstrate how a VPN can be used to bypass geographical content restrictions.

💡Unilateral Decision

The term 'unilateral decision' in the script refers to the independent choice made by countries regarding their time zone and relation to the International Date Line. It emphasizes the flexibility of the Date Line and how it can be adjusted based on a single country's decision, as illustrated with the examples of Kiribati and Samoa.

💡Notch

The 'notch' in the script refers to the indentation in the International Date Line that was made to accommodate the island nation of Kiribati. This term is used to describe the physical bend in the line on the map, which was created to ensure the entire nation is on the same calendar day.

Highlights

The creator made a promise to make a video about the International Date Line and its complexities.

The International Date Line can cause confusion, like traveling from Hawaii to New Zealand and experiencing days out of order.

Different sources like Google Maps, CIA fact book, and PacIOOS have slightly different representations of the International Date Line.

The International Date Line is not a fixed border but a conceptual line dividing time zones.

The video explains the concept of time zones and how they are measured from the Prime Meridian in Greenwich.

The International Date Line zigzags to accommodate different countries' and islands' time preferences.

The line avoids splitting Russian territory and Alaskan islands into different days.

Kiribati, an island nation, had to decide on which side of the Date Line to be on for practical reasons.

The Date Line's irregularities are due to political and practical decisions rather than geographical necessity.

Different mapping organizations may not precisely agree on the exact path of the International Date Line.

Google Maps and PacIOOS have discrepancies in their mapping of the Date Line, with Google Maps being incorrect in some instances.

The International Date Line is flexible and can be changed by countries based on their preferences.

The video uses a top-down view of the Earth to explain the concept of the Date Line in an intuitive way.

The creator emphasizes the importance of understanding the Date Line despite its conceptual challenges.

Aitutaki, a beautiful Pacific island, is showcased as an example of the natural beauty the Date Line traverses.

The video concludes by emphasizing the flexibility and practicality of the International Date Line over strict geographical accuracy.

The creator expresses a slight existential crisis upon discovering Google Maps' inaccuracies but acknowledges the Date Line's conceptual nature.

The video is sponsored by ExpressVPN, which is highlighted as a tool for secure and flexible internet connections.

Transcripts

- A while back, I made a promise.

(soft music)

Someday, I'll make a video about this whole messy debacle.

So today I intend to make good on that promise.

Here we go.

(upbeat music)

This line is weird.

It's not a border,

but I guess it kind of is, it divides something.

If it's Monday evening

and you fly from Hawaii to New Zealand,

you'll cross into Tuesday evening and then back

into Monday evening and then back into Tuesday evening.

And because you've been flying for a while,

now it's probably Wednesday morning.

You just jumped

from Monday to Wednesday on a nine hour flight.

Better yet, jump in your boat on a Tuesday afternoon

and go a few hundred kilometers south.

And suddenly you're watching the sunset on a Monday

because you drove south in your boat.

Wait what?

So I want to understand this line.

So naturally the first thing I do is go

into After Effects and try to map it out.

As I scoured the internet for good data on this,

I realized that everyone's international dateline

is slightly different,

from Google Maps to the CIA fact book,

to the Pacific Island Ocean Observing System,

which is an organization that has the elegant acronym

of PacIOOS.

Anyway, I spent the day scraping all the data I could,

and trying to map this line.

Looks like it's 195 miles or around 300 kilometers.

That's a huge difference.

There are entire islands with people that Google

says are on one side and PacIOOS say are on the other.

Who's right here?

Before we settle that,

I want to dig into what this line even is

and why it looks the way it does.

Okay, so this whole crossing a line

and passing over a day and going back in time

and all of that, is a little bit hard

for I know my brain to get around.

And I imagine that a lot of you came to this video,

hoping that you will leave this video

with a firm grasp of what The International Date Line is.

So I'm going to dive in and explain it the best I can.

First, let's look at the earth from top down.

So we're looking at the earth from above, like top down.

Here's great Britain over here.

And of course,

we've got our beautiful sun shining light onto our earth

which gives us day and night.

Land that is rotating into this light is seeing a sunrise,

land that is transitioning out of this light

is seeing a sunset.

And it's the relationship

to this light that we measure our time with,

with noon being the point where we are right smack dab

in the middle of the sun's light.

So right now it's noon in Florida.

Okay, you already know this, but I'm setting it up here

because it helps the Date Line makes sense.

Let's go back to Britain, which is upside down right now

because remember we're looking down on the globe,

like we're looking down at the North Pole.

Also, this circle is pretty sloppy.

Let's clean it up and make it a nice square

so you can keep your eye on it.

It's important because all time is measured from here,

technically in a little observatory called Greenwich.

So let's say, here in London, it is the middle of the day,

on a Monday.

Okay, so it's noon on a Monday,

the sun is shining right on London.

So let's freeze time and look what's happening

a few thousand kilometers east of here

in the middle of Russia, it's 6:00 PM.

The sun is setting.

It's still Monday, but the sun is setting on Monday.

At this same moment, frozen in time, over here in East Asia,

we've got China and there's Japan.

It's still noon in London, remember that,

but it's late over here.

The sun has gone down.

It's 9:00 PM in Japan.

It's still Monday.

It's just late.

The sun went down hours ago.

These people are finishing Monday.

It's like the middle of the night on Monday.

It's noon in London.

Let's zoom out and realize that it's Monday,

all around the world.

The more west you go from London

it is actually earlier on Monday.

East of London, it's late on a Monday night,

like we just saw.

It's later and later the more east you go.

This is The International Date Line.

It divides whether or not it's late on a Monday night

or early on a Monday morning.

Now let's press play

on the globe and watch it rotate into a new day.

Remember that these guys right here are like

at 11:00 PM, basically midnight.

They're about to start Tuesday.

I'll keep Monday as this orange circle

and I'll use green for Tuesday.

Okay, press play.

(upbeat music)

Okay stop, zoom in, here in the middle of the Pacific.

It's almost 11:00 AM on Tuesday, right?

You're 12 hours ahead of Greenwich Mean Time in London.

Go right over this line and you'll still be around 11:00 AM.

The sun is still shining in the same way,

but now you are 12 hours behind Greenwich Mean Time,

but it's still Monday.

You're 12 hours behind Greenwich.

It hasn't passed into a new day yet.

And that's how you're able to cross this line

and go back a day or forward a day,

even though you only go a few hundred kilometers.

Okay.

I'm sure you're tired of looking at this top down globe.

It's kind of disorienting and not super intuitive.

So let's see what this looks like on a map,

on a regular old map.

Here we are in the same exact scenario.

It's around 11:00 AM right here.

And yet it's Tuesday here and Monday over here.

I'm going to call this side which is later

than London's time, it's east of London, the Tuesday side.

And I'm going to call this side,

which is behind London or west of London, the Monday side.

I'll just use that, that's my own little terminology.

I'm gonna start using that.

And no one else uses it like that,

but I'm just going to for the rest of this video, okay.

I'm interrupting all of this conceptual non-intuitive stuff

for a little intermission.

I want you to just look at this for a second.

There are a bunch of beautiful islands in the Pacific.

This one's called Aitutaki.

That's really what it's called.

That was my best accent.

Just remember that The International Date Line runs

through some of the most beautiful ocean in the world,

and it's worth just looking at it for a second.

Let's get going on this question of why it's different

on every map.

Why does this line look so messed up,

and what's with this notch?

And why can't anyone agree on what it should look like?

This is the part that I knew nothing about.

And it's fascinating.

Technically, according to our little conceptual model

that we just did, the line should just be like this,

a straight line that's on the exact opposite side

of the world as Greenwich.

Meaning if Greenwich is zero,

this would be the 180th Meridian.

But as I've said many times before,

nature isn't super good at straight lines.

So instead it looks like this.

It starts out following the 180th Meridian as it should.

Then it splits off right here to make sure

that this Russian Island and then the very eastern tip

of Russia don't get sliced in two,

to become part of different days.

As it accommodates Russia.

It passes right here between Russia and Alaska.

If you zoom in,

you'll see that it passes right through these two islands.

These islands are just a few kilometers away

from each other.

The sun sets at the same time on both these islands,

they're right next to each other.

The difference is the sun is setting

on a Tuesday here and on a Monday here.

After Russia, the line heads back west to meet up with

the 180th, but it passes it in order to keep all

of these islands on this side because they belong to Alaska.

This notch goes all the way over to accommodate this island

of Alaska, which is this tiny outpost of 21 people.

It looks like the most western part of the United States,

but really because it's on the other side

of the 180th Meridian, everything left of this line

is actually in the Eastern hemisphere.

So this is technically the eastern most part

of the US but whatever, it doesn't really matter.

It's all, these are all fake lines anyway.

Okay, so we've zigzagged back and forth,

crossing the 180th Meridian a few times

to accommodate Russia and the United States.

It finally gets back onto the 180th

and starts following it south for a really long time.

Once it gets to the equator, we begin the big game

of whose side are you on?

All these islands in the Pacific

and there are loads of them,

have to make a decision on whether

or not they want to be the first people to start new days,

or the last people to end those days.

We've got this big notch here

which basically exists to accommodate Kiribati,

which is an island nation of just like 112,000 people.

But this nation is spread

across a huge swath of ocean, which spans an area greater

than the continental United States.

It's huge.

It bounces around here to make sure that Kiribati

is on the Eastern hemisphere time zone

with Australia and Asia,

and that other nations like the Cook Islands

are on the western part, like with the United States.

It dips down here between Samoa,

which is on the Tuesday side and the islands

of American Samoa, which are on the Monday side,

same with the United States.

From here, the line heads straight south,

but not along the 180th like it should,

instead it follows closer to like the 172nd.

This has meant to allow a bunch

of these island nations to stay in the Tuesday side

so that they can be on the same date

as big regional countries like Australia or New Zealand.

Then finally it meets up with the 180th Meridian

and it follows it all the way down to Antarctica.

Okay.

So that is this line and why it exists

and why it zigzags and all of its twists and turns.

So our two important questions here,

why does it look so weird,

and why is it different on every map?

The first one we can kind of answer pretty easily

after seeing where the line goes,

which is this line is really flexible.

It's not a real border.

It doesn't denote any land that somebody owns.

A regular border is defined

through conflict or negotiation,

and it denotes the sovereignty of a country.

You own this and I own that.

That is what a normal border does.

This doesn't do that.

The Date Line is a decision

that every country can make for itself.

When they're in the Pacific they can decide,

oh, I want to be on the same date as Australia and Japan,

or I want to be on the same date as Hawaii

and the United States.

That is a unilateral decision

that no country has to negotiate with others to make.

The Pacific nation of Samoa has decided

it would be better off if it observed

a time zone closer to that of Australia and New Zealand.

So it's declared, it will switch to our side

of The International Date Line

Before that big notch existed,

half of Kiribati was in the Tuesday side

and the other half was in the Monday side,

which just made it really hard where it was like Friday

on this side, and if people wanted to get

in touch with people in their country,

it was already Saturday on their side

and so they were off for the weekend.

So they unilaterally decided in 1995 to just change the line

and put the entire country on the Tuesday side.

So every country decides how they want to do it,

and because of that, it's changed dramatically

over the years as countries just make their own decision

on what date and times that they want to be in.

So now to my second question and the big one

that I was very curious about which is who's right?

After a day of fixating on this question

and mapping and doing all this stuff on the computer,

it all came down to this moment.

You have these two versions of the notch that are different.

The black one is Google Maps.

This is how Google Maps displays it on all

of their different platforms.

And this yellow one is from that PacIOOS,

the Pacific observer something I don't really remember,

but it's like a big authority for the Pacific Ocean.

Remember that this is the Monday side

and this is the Tuesday side, same time, different dates.

As I zoomed around this, I saw these islands.

Google says that these islands are

on the Tuesday side, the one day ahead inside.

Whereas PacIOOS says that these are on the Monday side,

meaning the one day behind side.

I checked the official time zone

for every one of these islands,

and discover that they all belong to the Cook Islands,

which is a set of islands connected to New Zealand.

But that is on GMT minus 10,

meaning it's 10 hours behind GMT,

not a bunch of hours in front of GMT.

In short, all of these islands are on Monday side.

PacIOOS has it right, and Google Maps has it wrong.

Wait, what?

Google Maps has something wrong.

Bit of an existential crisis I've been going

through the past couple of days.

I want to be wrong on this.

In fact, if somebody comments and points out a flaw

in my logic or my analysis here,

I will be grateful for that,

because this is something that, I mean,

I have a really deep appreciation for Google Maps

and all of the wonderful mapping that they do,

but I think they got this wrong.

Somebody prove me wrong, please.

And if not, my world view has just shifted slightly.

But here's the thing, at the end of the day,

it doesn't really matter.

The fact that Google Maps didn't painstakingly weave

it's line through all of these islands,

is kind of an indication that these borders,

these fake borders, these lines don't actually

do anything besides describe the preference

on how different countries want to measure their time.

It doesn't give anyone extra land.

It doesn't give anyone extra waters or minerals

or any of this stuff

that usually make lines really important.

In this case, we're describing a preference.

And so I'm sure that these mapping organizations

haven't cared too much about getting the shape perfectly

in this vast swath of ocean that is mostly uninhabited.

That's The International Date Line.

I want to hear thoughts and feedback from everyone

and thank you for watching.

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You probably have been to.

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And one thing I realized is that there are a lot

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Lord of the Rings for example, that's where a VPN comes in.

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Thank you, ExpressVPN for supporting this channel.

And thank you for watching.

I'll see you in the next one.