National identities and rivalries still drive changes
In early January the sun does not rise in Kashgar, in China’s far west, until after 10am. Across the border, in eastern Afghanistan, it rises before 7am. That difference is the greatest jump in time across any land border on earth. By degrees of longitude Beijing, more than 3,000km to the east, should be about two and a half hours ahead of Kashgar. But when the People’s Republic of China was founded in 1949 it dropped the previous five official time zones and brought its citizens onto one, shared “Beijing time”.
The groundwork for a system of global time zones was laid at the International Meridian Conference of 1884. But it took several decades to be adopted around the world. With no international body in charge, countries can choose their own zone. There are common-sense and health reasons for them—or their constituent regions—to stick close to solar time. This can be thought of as a place’s natural time, when the clock would show noon when the sun is at its zenith. Yet for economic and political factors, as bleary-eyed residents of Kashgar could testify, they may choose otherwise.
J
F
M
A
M
J
J
A
S
O
N
D
Mapping the hour of sunrise globally shows time zones following national and, sometimes, regional boundaries, and slicing through the oceans.
Sunrise in local time
Cycling through the year, dark mornings sweep in to consume each pole in turn.
But there are also other places, away from extreme latitudes, that shade blue. These are the places—such as far-western China—where the clock runs far behind solar time, and sunrise happens late in locals’ day.
Not all time-zone changes are as extreme as China’s. Other countries may just tweak their time to assert their political identity, or to add weight to alliances and rivalries. In 2023, a year after it assumed the relevant power from Denmark, Greenland moved its clocks on by one hour, to ensure a greater overlap with business hours in Europe. A couple of remote places deviate from the territory’s primary time zone. In the north-west the American-operated Pituffik Space Base, which previously lagged the rest of the territory by an hour, is now two hours behind.
Greenland
J
F
M
A
M
J
J
A
S
O
N
D
Sunrise in local time
Nuuk, 2023
2024
Spain continues to use Central European Time when, by geography, it should be an hour earlier. General Francisco Franco, the country’s then-dictator, changed Spain’s time zone in 1940 to align with Nazi Germany. The clocks were never changed back. By contrast, in 2015 North Korea marked the 70th anniversary of the liberation of Korea from Japanese occupation by shifting to “Pyongyang time”. This was 30 minutes behind the time zone the countries had previously shared. (Three years later, admittedly, it reversed the change, though the rationale was that this was a gesture of reconciliation with South Korea.) Even daylight saving can be manipulated to reinforce opposition. When the Palestinian Authority (PA) gained partial control over the West Bank and Gaza in 1993 it adopted a different daylight-saving schedule from Israel. And when Hamas took over Gaza in 2007, it chose to change the clocks on a different day from the PA-run West Bank.
Most countries need only one time zone. But in larger ones governments have a choice. Some, like China, impose one on the entire populace in the name of unity; in 2024 Kazakhstan turned its two zones into one to “eliminate time barriers” between its people. In Xinjiang, in western China, many among the local Uyghur population prefer to use “Xinjiang time”. This informal time zone, closer to natural solar time, is two hours behind the official “Beijing time”. Local Han Chinese, the dominant national ethnic group, are more likely to adhere to the latter. People socialising across ethnic groups have to keep track of which time appointments are made in.
China
J
F
M
A
M
J
J
A
S
O
N
D
Beijing
Lhasa, Tibet
Kashgar, Xinjiang
In Russia the preponderance of time zones is a source of pride. In 2009 the then-president, Dmitry Medvedev, said Russia’s 11 zones had been seen as “a vivid symbol of our country’s greatness”. Nevertheless, he argued, for reasons of efficiency, the number of zones should be reduced. In 2010 Russia dropped to nine zones. But the land’s vastness and northerly latitude made shifts away from solar time particularly unpopular, and protests followed in the far east. In 2014 Russia returned to 11, albeit slightly different, zones.
Russia
J
F
M
A
M
J
J
A
S
O
N
D
Imposing time offers an easy way to show who is in charge. The portions of Ukraine taken over by Russia since the invasion of 2022 have been moved onto Moscow time. Crimea has been on Moscow time since Russia occupied the peninsula in 2014. The transition was marked by a ceremony to adjust the clock in the railway station in Simferopol. It is a pattern of events already familiar in Russian-occupied parts of Georgia.
In an age where every digital transaction and communication is time-stamped, changes to time zones need to be conveyed to computers and phones in affected areas. Updates are tracked in the “tz database”, a volunteer-run operation that monitors government announcements and media reports and is relied on by telephone and computer companies. But alterations may still cause technical trouble. Users of Apple products in Russia complained when the country’s time-zone changes of the 2010s did not make it onto all devices. Muscovites ended up setting their phones to Azerbaijani or Armenian time.
The worst disruptors are governments that make last-minute changes to the dates of daylight saving time (DST). Lebanon’s late decision to delay the start of DST in 2023 led to chaos. It was intended to help local Muslims observing Ramadan, which is determined by the lunar calendar, so they would not have to delay the breaking of their fasts. Compliance by state institutions, religious organisations and technology companies varied. Google and Apple showed different times.
In Morocco, the changing interplay between Ramadan and DST left the government changing clocks up to four times a year. Now, though, they are permanently set to DST, save for Ramadan when they shift back an hour.
Morocco
2007
2010
2013
2016
2019
2022
2024
Some countries have had enough of clock changes, or the shifting of time from the natural cycles of the sun. Mexico went further than Morocco and abandoned DST completely in 2022, though a string of cities along the northern border prefer to remain synchronised with America. What is simple and natural can override other concerns. In 2021, a decade after independence from Sudan, South Sudan moved its clocks one hour back, even though its biggest trade partners remain on East Africa Time. But as the official announcement described it, sometimes you just want to set time by your “real location on the globe”. ■
Correction (March 31st 2025): This article originally stated that by geography the time in Spain should be an hour later than Central European Time, rather than earlier.
National identities and rivalries still drive changes
In early January the sun does not rise in Kashgar, in China’s far west, until after 10am. Across the border, in eastern Afghanistan, it rises before 7am. That difference is the greatest jump in time across any land border on earth. By degrees of longitude Beijing, more than 3,000km to the east, should be about two and a half hours ahead of Kashgar. But when the People’s Republic of China was founded in 1949 it dropped the previous five official time zones and brought its citizens onto one, shared “Beijing time”.
The groundwork for a system of global time zones was laid at the International Meridian Conference of 1884. But it took several decades to be adopted around the world. With no international body in charge, countries can choose their own zone. There are common-sense and health reasons for them—or their constituent regions—to stick close to solar time. This can be thought of as a place’s natural time, when the clock would show noon when the sun is at its zenith. Yet for economic and political factors, as bleary-eyed residents of Kashgar could testify, they may choose otherwise.
J
F
M
A
M
J
J
A
S
O
N
D
Mapping the hour of sunrise globally shows time zones following national and, sometimes, regional boundaries, and slicing through the oceans.
Sunrise in local time
Cycling through the year, dark mornings sweep in to consume each pole in turn.
But there are also other places, away from extreme latitudes, that shade blue. These are the places—such as far-western China—where the clock runs far behind solar time, and sunrise happens late in locals’ day.
Not all time-zone changes are as extreme as China’s. Other countries may just tweak their time to assert their political identity, or to add weight to alliances and rivalries. In 2023, a year after it assumed the relevant power from Denmark, Greenland moved its clocks on by one hour, to ensure a greater overlap with business hours in Europe. A couple of remote places deviate from the territory’s primary time zone. In the north-west the American-operated Pituffik Space Base, which previously lagged the rest of the territory by an hour, is now two hours behind.
Greenland
J
F
M
A
M
J
J
A
S
O
N
D
Sunrise in local time
Nuuk, 2023
2024
Spain continues to use Central European Time when, by geography, it should be an hour earlier. General Francisco Franco, the country’s then-dictator, changed Spain’s time zone in 1940 to align with Nazi Germany. The clocks were never changed back. By contrast, in 2015 North Korea marked the 70th anniversary of the liberation of Korea from Japanese occupation by shifting to “Pyongyang time”. This was 30 minutes behind the time zone the countries had previously shared. (Three years later, admittedly, it reversed the change, though the rationale was that this was a gesture of reconciliation with South Korea.) Even daylight saving can be manipulated to reinforce opposition. When the Palestinian Authority (PA) gained partial control over the West Bank and Gaza in 1993 it adopted a different daylight-saving schedule from Israel. And when Hamas took over Gaza in 2007, it chose to change the clocks on a different day from the PA-run West Bank.
Most countries need only one time zone. But in larger ones governments have a choice. Some, like China, impose one on the entire populace in the name of unity; in 2024 Kazakhstan turned its two zones into one to “eliminate time barriers” between its people. In Xinjiang, in western China, many among the local Uyghur population prefer to use “Xinjiang time”. This informal time zone, closer to natural solar time, is two hours behind the official “Beijing time”. Local Han Chinese, the dominant national ethnic group, are more likely to adhere to the latter. People socialising across ethnic groups have to keep track of which time appointments are made in.
China
J
F
M
A
M
J
J
A
S
O
N
D
Beijing
Lhasa, Tibet
Kashgar, Xinjiang
In Russia the preponderance of time zones is a source of pride. In 2009 the then-president, Dmitry Medvedev, said Russia’s 11 zones had been seen as “a vivid symbol of our country’s greatness”. Nevertheless, he argued, for reasons of efficiency, the number of zones should be reduced. In 2010 Russia dropped to nine zones. But the land’s vastness and northerly latitude made shifts away from solar time particularly unpopular, and protests followed in the far east. In 2014 Russia returned to 11, albeit slightly different, zones.
Russia
J
F
M
A
M
J
J
A
S
O
N
D
Imposing time offers an easy way to show who is in charge. The portions of Ukraine taken over by Russia since the invasion of 2022 have been moved onto Moscow time. Crimea has been on Moscow time since Russia occupied the peninsula in 2014. The transition was marked by a ceremony to adjust the clock in the railway station in Simferopol. It is a pattern of events already familiar in Russian-occupied parts of Georgia.
In an age where every digital transaction and communication is time-stamped, changes to time zones need to be conveyed to computers and phones in affected areas. Updates are tracked in the “tz database”, a volunteer-run operation that monitors government announcements and media reports and is relied on by telephone and computer companies. But alterations may still cause technical trouble. Users of Apple products in Russia complained when the country’s time-zone changes of the 2010s did not make it onto all devices. Muscovites ended up setting their phones to Azerbaijani or Armenian time.
The worst disruptors are governments that make last-minute changes to the dates of daylight saving time (DST). Lebanon’s late decision to delay the start of DST in 2023 led to chaos. It was intended to help local Muslims observing Ramadan, which is determined by the lunar calendar, so they would not have to delay the breaking of their fasts. Compliance by state institutions, religious organisations and technology companies varied. Google and Apple showed different times.
In Morocco, the changing interplay between Ramadan and DST left the government changing clocks up to four times a year. Now, though, they are permanently set to DST, save for Ramadan when they shift back an hour.
Morocco
2007
2010
2013
2016
2019
2022
2024
Some countries have had enough of clock changes, or the shifting of time from the natural cycles of the sun. Mexico went further than Morocco and abandoned DST completely in 2022, though a string of cities along the northern border prefer to remain synchronised with America. What is simple and natural can override other concerns. In 2021, a decade after independence from Sudan, South Sudan moved its clocks one hour back, even though its biggest trade partners remain on East Africa Time. But as the official announcement described it, sometimes you just want to set time by your “real location on the globe”. ■
Correction (March 31st 2025): This article originally stated that by geography the time in Spain should be an hour later than Central European Time, rather than earlier.
National identities and rivalries still drive changes
In early January the sun does not rise in Kashgar, in China’s far west, until after 10am. Across the border, in eastern Afghanistan, it rises before 7am. That difference is the greatest jump in time across any land border on earth. By degrees of longitude Beijing, more than 3,000km to the east, should be about two and a half hours ahead of Kashgar. But when the People’s Republic of China was founded in 1949 it dropped the previous five official time zones and brought its citizens onto one, shared “Beijing time”.
The groundwork for a system of global time zones was laid at the International Meridian Conference of 1884. But it took several decades to be adopted around the world. With no international body in charge, countries can choose their own zone. There are common-sense and health reasons for them—or their constituent regions—to stick close to solar time. This can be thought of as a place’s natural time, when the clock would show noon when the sun is at its zenith. Yet for economic and political factors, as bleary-eyed residents of Kashgar could testify, they may choose otherwise.
J
F
M
A
M
J
J
A
S
O
N
D
Mapping the hour of sunrise globally shows time zones following national and, sometimes, regional boundaries, and slicing through the oceans.
Sunrise in local time
Cycling through the year, dark mornings sweep in to consume each pole in turn.
But there are also other places, away from extreme latitudes, that shade blue. These are the places—such as far-western China—where the clock runs far behind solar time, and sunrise happens late in locals’ day.
Not all time-zone changes are as extreme as China’s. Other countries may just tweak their time to assert their political identity, or to add weight to alliances and rivalries. In 2023, a year after it assumed the relevant power from Denmark, Greenland moved its clocks on by one hour, to ensure a greater overlap with business hours in Europe. A couple of remote places deviate from the territory’s primary time zone. In the north-west the American-operated Pituffik Space Base, which previously lagged the rest of the territory by an hour, is now two hours behind.
Greenland
J
F
M
A
M
J
J
A
S
O
N
D
Sunrise in local time
Nuuk, 2023
2024
Spain continues to use Central European Time when, by geography, it should be an hour earlier. General Francisco Franco, the country’s then-dictator, changed Spain’s time zone in 1940 to align with Nazi Germany. The clocks were never changed back. By contrast, in 2015 North Korea marked the 70th anniversary of the liberation of Korea from Japanese occupation by shifting to “Pyongyang time”. This was 30 minutes behind the time zone the countries had previously shared. (Three years later, admittedly, it reversed the change, though the rationale was that this was a gesture of reconciliation with South Korea.) Even daylight saving can be manipulated to reinforce opposition. When the Palestinian Authority (PA) gained partial control over the West Bank and Gaza in 1993 it adopted a different daylight-saving schedule from Israel. And when Hamas took over Gaza in 2007, it chose to change the clocks on a different day from the PA-run West Bank.
Most countries need only one time zone. But in larger ones governments have a choice. Some, like China, impose one on the entire populace in the name of unity; in 2024 Kazakhstan turned its two zones into one to “eliminate time barriers” between its people. In Xinjiang, in western China, many among the local Uyghur population prefer to use “Xinjiang time”. This informal time zone, closer to natural solar time, is two hours behind the official “Beijing time”. Local Han Chinese, the dominant national ethnic group, are more likely to adhere to the latter. People socialising across ethnic groups have to keep track of which time appointments are made in.
China
J
F
M
A
M
J
J
A
S
O
N
D
Beijing
Lhasa, Tibet
Kashgar, Xinjiang
In Russia the preponderance of time zones is a source of pride. In 2009 the then-president, Dmitry Medvedev, said Russia’s 11 zones had been seen as “a vivid symbol of our country’s greatness”. Nevertheless, he argued, for reasons of efficiency, the number of zones should be reduced. In 2010 Russia dropped to nine zones. But the land’s vastness and northerly latitude made shifts away from solar time particularly unpopular, and protests followed in the far east. In 2014 Russia returned to 11, albeit slightly different, zones.
Russia
J
F
M
A
M
J
J
A
S
O
N
D
Imposing time offers an easy way to show who is in charge. The portions of Ukraine taken over by Russia since the invasion of 2022 have been moved onto Moscow time. Crimea has been on Moscow time since Russia occupied the peninsula in 2014. The transition was marked by a ceremony to adjust the clock in the railway station in Simferopol. It is a pattern of events already familiar in Russian-occupied parts of Georgia.
In an age where every digital transaction and communication is time-stamped, changes to time zones need to be conveyed to computers and phones in affected areas. Updates are tracked in the “tz database”, a volunteer-run operation that monitors government announcements and media reports and is relied on by telephone and computer companies. But alterations may still cause technical trouble. Users of Apple products in Russia complained when the country’s time-zone changes of the 2010s did not make it onto all devices. Muscovites ended up setting their phones to Azerbaijani or Armenian time.
The worst disruptors are governments that make last-minute changes to the dates of daylight saving time (DST). Lebanon’s late decision to delay the start of DST in 2023 led to chaos. It was intended to help local Muslims observing Ramadan, which is determined by the lunar calendar, so they would not have to delay the breaking of their fasts. Compliance by state institutions, religious organisations and technology companies varied. Google and Apple showed different times.
In Morocco, the changing interplay between Ramadan and DST left the government changing clocks up to four times a year. Now, though, they are permanently set to DST, save for Ramadan when they shift back an hour.
Morocco
2007
2010
2013
2016
2019
2022
2024
Some countries have had enough of clock changes, or the shifting of time from the natural cycles of the sun. Mexico went further than Morocco and abandoned DST completely in 2022, though a string of cities along the northern border prefer to remain synchronised with America. What is simple and natural can override other concerns. In 2021, a decade after independence from Sudan, South Sudan moved its clocks one hour back, even though its biggest trade partners remain on East Africa Time. But as the official announcement described it, sometimes you just want to set time by your “real location on the globe”. ■
Correction (March 31st 2025): This article originally stated that by geography the time in Spain should be an hour later than Central European Time, rather than earlier.
National identities and rivalries still drive changes
In early January the sun does not rise in Kashgar, in China’s far west, until after 10am. Across the border, in eastern Afghanistan, it rises before 7am. That difference is the greatest jump in time across any land border on earth. By degrees of longitude Beijing, more than 3,000km to the east, should be about two and a half hours ahead of Kashgar. But when the People’s Republic of China was founded in 1949 it dropped the previous five official time zones and brought its citizens onto one, shared “Beijing time”.
The groundwork for a system of global time zones was laid at the International Meridian Conference of 1884. But it took several decades to be adopted around the world. With no international body in charge, countries can choose their own zone. There are common-sense and health reasons for them—or their constituent regions—to stick close to solar time. This can be thought of as a place’s natural time, when the clock would show noon when the sun is at its zenith. Yet for economic and political factors, as bleary-eyed residents of Kashgar could testify, they may choose otherwise.
J
F
M
A
M
J
J
A
S
O
N
D
Mapping the hour of sunrise globally shows time zones following national and, sometimes, regional boundaries, and slicing through the oceans.
Sunrise in local time
Cycling through the year, dark mornings sweep in to consume each pole in turn.
But there are also other places, away from extreme latitudes, that shade blue. These are the places—such as far-western China—where the clock runs far behind solar time, and sunrise happens late in locals’ day.
Not all time-zone changes are as extreme as China’s. Other countries may just tweak their time to assert their political identity, or to add weight to alliances and rivalries. In 2023, a year after it assumed the relevant power from Denmark, Greenland moved its clocks on by one hour, to ensure a greater overlap with business hours in Europe. A couple of remote places deviate from the territory’s primary time zone. In the north-west the American-operated Pituffik Space Base, which previously lagged the rest of the territory by an hour, is now two hours behind.
Greenland
J
F
M
A
M
J
J
A
S
O
N
D
Sunrise in local time
Nuuk, 2023
2024
Spain continues to use Central European Time when, by geography, it should be an hour earlier. General Francisco Franco, the country’s then-dictator, changed Spain’s time zone in 1940 to align with Nazi Germany. The clocks were never changed back. By contrast, in 2015 North Korea marked the 70th anniversary of the liberation of Korea from Japanese occupation by shifting to “Pyongyang time”. This was 30 minutes behind the time zone the countries had previously shared. (Three years later, admittedly, it reversed the change, though the rationale was that this was a gesture of reconciliation with South Korea.) Even daylight saving can be manipulated to reinforce opposition. When the Palestinian Authority (PA) gained partial control over the West Bank and Gaza in 1993 it adopted a different daylight-saving schedule from Israel. And when Hamas took over Gaza in 2007, it chose to change the clocks on a different day from the PA-run West Bank.
Most countries need only one time zone. But in larger ones governments have a choice. Some, like China, impose one on the entire populace in the name of unity; in 2024 Kazakhstan turned its two zones into one to “eliminate time barriers” between its people. In Xinjiang, in western China, many among the local Uyghur population prefer to use “Xinjiang time”. This informal time zone, closer to natural solar time, is two hours behind the official “Beijing time”. Local Han Chinese, the dominant national ethnic group, are more likely to adhere to the latter. People socialising across ethnic groups have to keep track of which time appointments are made in.
China
J
F
M
A
M
J
J
A
S
O
N
D
Beijing
Lhasa, Tibet
Kashgar, Xinjiang
In Russia the preponderance of time zones is a source of pride. In 2009 the then-president, Dmitry Medvedev, said Russia’s 11 zones had been seen as “a vivid symbol of our country’s greatness”. Nevertheless, he argued, for reasons of efficiency, the number of zones should be reduced. In 2010 Russia dropped to nine zones. But the land’s vastness and northerly latitude made shifts away from solar time particularly unpopular, and protests followed in the far east. In 2014 Russia returned to 11, albeit slightly different, zones.
Russia
J
F
M
A
M
J
J
A
S
O
N
D
Imposing time offers an easy way to show who is in charge. The portions of Ukraine taken over by Russia since the invasion of 2022 have been moved onto Moscow time. Crimea has been on Moscow time since Russia occupied the peninsula in 2014. The transition was marked by a ceremony to adjust the clock in the railway station in Simferopol. It is a pattern of events already familiar in Russian-occupied parts of Georgia.
In an age where every digital transaction and communication is time-stamped, changes to time zones need to be conveyed to computers and phones in affected areas. Updates are tracked in the “tz database”, a volunteer-run operation that monitors government announcements and media reports and is relied on by telephone and computer companies. But alterations may still cause technical trouble. Users of Apple products in Russia complained when the country’s time-zone changes of the 2010s did not make it onto all devices. Muscovites ended up setting their phones to Azerbaijani or Armenian time.
The worst disruptors are governments that make last-minute changes to the dates of daylight saving time (DST). Lebanon’s late decision to delay the start of DST in 2023 led to chaos. It was intended to help local Muslims observing Ramadan, which is determined by the lunar calendar, so they would not have to delay the breaking of their fasts. Compliance by state institutions, religious organisations and technology companies varied. Google and Apple showed different times.
In Morocco, the changing interplay between Ramadan and DST left the government changing clocks up to four times a year. Now, though, they are permanently set to DST, save for Ramadan when they shift back an hour.
Morocco
2007
2010
2013
2016
2019
2022
2024
Some countries have had enough of clock changes, or the shifting of time from the natural cycles of the sun. Mexico went further than Morocco and abandoned DST completely in 2022, though a string of cities along the northern border prefer to remain synchronised with America. What is simple and natural can override other concerns. In 2021, a decade after independence from Sudan, South Sudan moved its clocks one hour back, even though its biggest trade partners remain on East Africa Time. But as the official announcement described it, sometimes you just want to set time by your “real location on the globe”. ■
Correction (March 31st 2025): This article originally stated that by geography the time in Spain should be an hour later than Central European Time, rather than earlier.