The whole list

204 facts about time zones and the clock change

None of these were remembered. Every one is either counted out of the world's time zone database or read off a line in it.

How the world is divided

#Fact
1There are 312 time zones in the world's official list, covering 247 countries and territories.
2Between them they use 39 different offsets from UTC in 2026.
3The clock spans 25 hours from end to end — more than a day, which is why there is always somewhere with a different date to yours.
4A time zone is not a country. 247 countries and territories share 312 zones between them, and some of the largest have a dozen each.
5The United States is split across 29 separate time zones.
6Russia is split across 27 separate time zones.
7Canada is split across 20 separate time zones.
8Brazil is split across 16 separate time zones.
934 of the world's zones are shared by more than one country — the clock is the same, so the time zone is the same entry.
1020 countries and territories keep the same clock as Puerto Rico — more than share any other single zone.
1173 different time zone abbreviations have been in use — and they are not unique, which is why a meeting invitation saying 'CST' could mean three different things.
12Antarctica is 11 hours wide on the clock: when it is noon in Palmer it is already 23:00 in Casey, Antarctica.
13Russia is 10 hours wide on the clock: when it is noon in Kaliningrad it is already 22:00 in Anadyr.
14The United States is 5 hours wide on the clock: when it is noon in Adak, Alaska it is already 17:00 in Detroit.
15Canada is 4.5 hours wide on the clock: when it is noon in Vancouver it is already 16:30 in St John's, Newfoundland.
16Greenland is 4 hours wide on the clock: when it is noon in Thule, Greenland it is already 16:00 in Danmarkshavn, Greenland.
17Mexico is 3 hours wide on the clock: when it is noon in Tijuana it is already 15:00 in Cancun.
18Brazil is 3 hours wide on the clock: when it is noon in Eirunepe it is already 15:00 in Noronha.
19Australia is 3 hours wide on the clock: when it is noon in Perth it is already 15:00 in Macquarie Island.
20214 of the world's 247 countries and territories keep a single clock from end to end. The other 33 need more than one.
21121 of the world's 312 time zones are filed under the Americas — 38% of the list.
2274 of the world's 312 time zones are filed under Asia — 23% of the list.
2338 of the world's 312 time zones are filed under Europe — 12% of the list.
2430 of the world's 312 time zones are filed under the Pacific — 9% of the list.
2519 of the world's 312 time zones are filed under Africa — 6% of the list.
2611 of the world's 312 time zones are filed under Australia — 3% of the list.
278 of the world's 312 time zones are filed under Antarctica — 2% of the list.
288 of the world's 312 time zones are filed under the Atlantic — 2% of the list.
293 of the world's 312 time zones are filed under the Indian Ocean — 0% of the list.

Offsets that are not whole hours

#Fact
3013 of the world's offsets are not a whole number of hours from UTC.
31the Marquesas Islands runs on UTC-9:30 — 30 minutes off the nearest whole hour.
32St John's, Newfoundland runs on UTC-3:30 — 30 minutes off the nearest whole hour.
33Tehran runs on UTC+3:30 — 30 minutes off the nearest whole hour.
34Kabul runs on UTC+4:30 — 30 minutes off the nearest whole hour.
35Colombo and Kolkata run on UTC+5:30 — 30 minutes off the nearest whole hour.
36Kathmandu runs on UTC+5:45 — 45 minutes off the nearest whole hour.
37Yangon runs on UTC+6:30 — 30 minutes off the nearest whole hour.
38Eucla, Australia runs on UTC+8:45 — 45 minutes off the nearest whole hour.
39Adelaide, Broken Hill, Australia and Darwin run on UTC+9:30 — 30 minutes off the nearest whole hour.
40Adelaide, Broken Hill, Australia and Lord Howe Island run on UTC+10:30 — 30 minutes off the nearest whole hour.
41the Chatham Islands runs on UTC+12:45 — 45 minutes off the nearest whole hour.
4213 of the world's 312 time zones are set to something other than a whole hour from UTC in January — about 4% of them.
43Lord Howe Island is only off the whole hour in July — the clock change is what puts it there.

Who changes and who does not

#Fact
44205 of the world's 312 time zones never touch their clocks in 2026. Only 107 do.
45Changing the clocks twice a year is the minority habit: it is what 34% of the world's time zones do.
46105 zones move their clocks by exactly one hour. Everyone else who moves them does something stranger.
47Troll, Antarctica moves its clocks by 2 hours, not by an hour — one of only two places on earth that does something other than a whole hour.
48Lord Howe Island moves its clocks by 30 minutes, not by an hour — one of only two places on earth that does something other than a whole hour.
49In Africa, 4 of 19 time zones change their clocks in 2026.
50In the Americas, 53 of 121 time zones change their clocks in 2026.
51In Antarctica, 2 of 8 time zones change their clocks in 2026.
52In Asia, 6 of 74 time zones change their clocks in 2026.
53In the Atlantic, 5 of 8 time zones change their clocks in 2026.
54In Australia, 6 of 11 time zones change their clocks in 2026.
55In Europe, 27 of 38 time zones change their clocks in 2026.
56Not one of the 3 time zones in the Indian Ocean changes its clocks in 2026.
57In the Pacific, 4 of 30 time zones change their clocks in 2026.
5853 of the world's 312 time zones have never moved their clocks for the summer. Not once, in the whole history of the record.
59Among the places that have never once used daylight saving: Abidjan, Bangkok and Bissau.
607 countries cannot agree with themselves: part of the country changes the clocks and part of it does not.
61In the United States, 27 of 29 time zones change the clocks and the other 2 do not.
62In Canada, 14 of 20 time zones change the clocks and the other 6 do not.
63In Mexico, 4 of 12 time zones change the clocks and the other 8 do not.
64In Australia, 7 of 12 time zones change the clocks and the other 5 do not.
65In Antarctica, 1 of 7 time zones changes the clocks and the other 6 do not.
66In Chile, 2 of 4 time zones change the clocks and the other 2 do not.
67In Greenland, 3 of 4 time zones change the clocks and the other 1 does not.

When it happens

#Fact
68There are 213 clock changes in the world in 2026, spread over 17 different days.
69The world's first clock change of 2026 is Casablanca's, on 15 February.
70The world's last clock change of 2026 is Adak, Alaska's, on 1 November.
71Most of the world moves its clocks at 02:00 local time — 139 of the 213 changes in 2026 happen then.
72the Chatham Islands moves its clocks at 02:45 local time, not at two in the morning like nearly everyone else.
73Easter Island moves its clocks at 22:00 local time, not at two in the morning like nearly everyone else.
74Nuuk and Scoresbysund, Greenland move their clocks at 23:00 local time, not at two in the morning like nearly everyone else.
75Clock changes cluster in two months: 94 of the 213 in 2026 happen in March.
76The southern hemisphere does it backwards: its clocks go forward in September and October, while the northern hemisphere's go back.
77The longest summer time in the world is El Aaiun, Western Sahara's: 330 days of the year on the moved clock.
78The shortest is Macquarie Island's, at 183 days.
79The middle of the pack is about 212 days — around 58% of the year, which makes 'summer time' a generous name for it.
80202 of the world's 213 clock changes in 2026 fall on a Sunday. Nobody wants to do this on a working morning.
81The exceptions fall on a Friday and Saturday — the places whose rule is tied to a date rather than to a weekend.
8294 of the world's clocks go forward in March.
838 of the world's clocks go forward in October.
844 of the world's clocks go forward in September.
8550 of the world's clocks go back in November.
8642 of the world's clocks go back in October.
8712 of the world's clocks go back in April.

How it started and how it went

#Fact
88The time zone database carries daylight saving rules going back to 1910.
89It also carries rules that run to 2086, because some countries have written their rules with no end date.
90134 separate sets of daylight saving rules have existed, one for each country or region that has ever kept its own schedule.
91Clocks have been moved by 7 different amounts over the years, not just by an hour.
92Double summer time is real: 22 rules in the database move the clocks by two hours.
9323 rules in the database move the clocks by half an hour.
941 rule in the database moves the clocks by twenty minutes.
951 rule in the database moves the clocks by ninety minutes.
9615 rules move the clocks BACKWARDS in summer — a negative daylight saving, where the standard time is the summer one and winter is the exception.
97The most rewritten entry in the database is Tijuana's: its offset from UTC has been redefined 23 times.
98Across every zone, the database records 1963 separate periods of 'the clock here was set like this' since records began.
99Paraguay last moved its clocks in 2024, after keeping daylight saving on and off since 1975.
100Iran last moved its clocks in 2022, after keeping daylight saving on and off since 1910.
101Syria last moved its clocks in 2022, after keeping daylight saving on and off since 1920.
102Fiji kept daylight saving from 1998 to 2021, then stopped.
103Samoa kept daylight saving from 2010 to 2021, then stopped.
104Brazil last moved its clocks in 2019, after keeping daylight saving on and off since 1931.
105Namibia kept daylight saving from 1994 to 2017, then stopped.
106Tonga kept daylight saving from 1999 to 2017, then stopped.
107Mongolia kept daylight saving from 1983 to 2016, then stopped.
108Azerbaijan kept daylight saving from 1997 to 2015, then stopped.
109Uruguay last moved its clocks in 2015, after keeping daylight saving on and off since 1923.
110Libya last moved its clocks in 2013, after keeping daylight saving on and off since 1951.
111Armenia tried daylight saving in 2011 and gave it up the same year.
112Armenia and 7 other countries kept daylight saving from 1981 to 2010, then stopped.
113The Falkland Islands last moved their clocks in 2010, after keeping daylight saving on and off since 1937.
114Mauritius kept daylight saving from 1982 to 2009, then stopped.
115Bangladesh tried daylight saving in 2009 and gave it up the same year.
116Pakistan kept daylight saving from 2002 to 2009, then stopped.
117Eucla, Australia and Perth kept daylight saving from 1974 to 2009, then stopped.
118Buenos Aires, Catamarca and 11 other places last moved their clocks in 2009, after keeping daylight saving on and off since 1930.
119San Luis tried daylight saving in 2007 and gave it up by 2009.
120Tunisia last moved its clocks in 2008, after keeping daylight saving on and off since 1939.
121Iraq kept daylight saving from 1982 to 2007, then stopped.
122Turkey last moved its clocks in 2006, after keeping daylight saving on and off since 1916.
123Guatemala kept daylight saving from 1973 to 2006, then stopped.
124Honduras kept daylight saving from 1987 to 2006, then stopped.
125Nicaragua kept daylight saving from 1979 to 2006, then stopped.
126Kyrgyzstan kept daylight saving from 1992 to 2005, then stopped.
127New Caledonia kept daylight saving from 1977 to 1997, then stopped.
128Lindeman tried daylight saving in 1992 and gave it up by 1994.
129Peru last moved its clocks in 1994, after keeping daylight saving on and off since 1938.
130Vanuatu kept daylight saving from 1973 to 1993, then stopped.
131Colombia tried daylight saving in 1992 and gave it up by 1993.
132Ecuador tried daylight saving in 1992 and gave it up by 1993.
133Brisbane and Lindeman kept daylight saving from 1971 to 1992, then stopped.
134Costa Rica kept daylight saving from 1979 to 1992, then stopped.
135Shanghai kept daylight saving from 1986 to 1991, then stopped.
136The Cook Islands kept daylight saving from 1978 to 1991, then stopped.
137The Philippines last moved their clocks in 1990, after keeping daylight saving on and off since 1936.
138South Korea last moved its clocks in 1988, after keeping daylight saving on and off since 1948.
139El Salvador tried daylight saving in 1987 and gave it up by 1988.
140Sudan and South Sudan kept daylight saving from 1970 to 1985, then stopped.
141Belize last moved its clocks in 1983, after keeping daylight saving on and off since 1918.
142Algeria last moved its clocks in 1980, after keeping daylight saving on and off since 1916.
143Barbados kept daylight saving from 1942 to 1980, then stopped.
144Hong Kong kept daylight saving from 1946 to 1979, then stopped.
145Taiwan kept daylight saving from 1946 to 1979, then stopped.
146Macau kept daylight saving from 1942 to 1979, then stopped.
147Guam kept daylight saving from 1959 to 1977, then stopped.
148The Dominican Republic kept daylight saving from 1966 to 1974, then stopped.
149Dawson and Whitehorse tried daylight saving in 1965 and gave it up the same year.
150Swift Current tried daylight saving in 1957 and gave it up by 1961.
151Regina and Swift Current last moved their clocks in 1959, after keeping daylight saving on and off since 1918.
152Japan tried daylight saving in 1948 and gave it up by 1951.
153Shanghai kept daylight saving from 1919 to 1949, then stopped.
154South Africa tried daylight saving in 1942 and gave it up by 1944.
155Malaysia kept daylight saving from 1935 to 1941, then stopped.
156Hobart and Macquarie Island have been moving the clocks, on and off, since 1916.
157Belgrade, Berlin and 18 other places have been moving the clocks, on and off, since 1916.
158Adak, Alaska, Anchorage and 37 other places have been moving the clocks, on and off, since 1918.
159Bermuda, Cambridge Bay and 19 other places have been moving the clocks, on and off, since 1918.
160Lebanon has been moving the clocks, on and off, since 1920.
161Auckland has been moving the clocks, on and off, since 1927.
162Coyhaique, Easter Island and 3 other places have been moving the clocks, on and off, since 1927.
163Cuba has been moving the clocks, on and off, since 1928.
164Egypt has been moving the clocks, on and off, since 1940.
165Israel and Palestine have been moving the clocks, on and off, since 1940.
166Adelaide and Broken Hill, Australia have been moving the clocks, on and off, since 1971.
167Melbourne has been moving the clocks, on and off, since 1971.
168Broken Hill, Australia, Norfolk and Sydney have been moving the clocks, on and off, since 1971.
169Ireland has been moving the clocks, on and off, since 1971.
170The Chatham Islands have been moving the clocks, on and off, since 1974.
171Andorra, Athens and 34 other places have been moving the clocks, on and off, since 1977.
172Poland has been moving the clocks, on and off, since 1977.
173Bulgaria, Moldova and Romania have been moving the clocks, on and off, since 1977.
174Azerbaijan and Cyprus have been moving the clocks, on and off, since 1979.
175Georgia has been moving the clocks, on and off, since 1979.
176Lord Howe Island has been moving the clocks, on and off, since 1981.
177Haiti has been moving the clocks, on and off, since 1983.
178Thule, Greenland has been moving the clocks, on and off, since 1991.
179Palestine has been moving the clocks, on and off, since 1999.
180Troll, Antarctica has been moving the clocks, on and off, since 2004.
181The most rewritten daylight saving schedule in the world is Palestine's: 110 separate amendments.
182Israel and Palestine have rewritten their daylight saving schedule 85 times.
183the United Kingdom, Gibraltar and Ireland have rewritten their daylight saving schedule 65 times.
184Western Sahara and Morocco have rewritten their daylight saving schedule 57 times.
185Brazil has rewritten its daylight saving schedule 57 times.
186Uruguay has rewritten its daylight saving schedule 48 times.
18727 leap seconds have been added to the world's clocks since 1972, each one a second that the earth had fallen behind.
188The most recent leap second was in 2016. There has not been one since, because the earth has been spinning slightly faster.
189A leap second is one second added to a minute, making it 61 seconds long. Almost nobody notices, and a few large computer systems fall over.
190The time zone database is on release 2026d. It is updated whenever a government changes its mind, which is several times a year.
191There have been 312 releases of the database, each one a country somewhere deciding something different about its clocks.
192The whole thing is public domain. Every phone, laptop and server on earth keeps time by the same volunteer-maintained text files.

The far edges of the map

#Fact
193The first place on earth to see a new day is Kiritimati, Kiribati, on UTC+14.
194The last is Niue, on UTC-11 — 25 hours behind the first.
195For one hour of every day, three different calendar dates are in use somewhere in the world at the same moment.
19612 of the world's time zones sit inside the Arctic or Antarctic circles, where for part of the year the sun does not set at all and daylight saving saves nothing.
197Antarctica has 8 time zones, and 2 of them still change the clocks — research stations keeping the hours of the country that supplies them.
198Danmarkshavn, Greenland moved its clock 3 hours forward in 1996 and left it there — a change of side, not a change of season.
199Casey, Antarctica moved its clock 3 hours back in 2023 and left it there — a change of side, not a change of season.
200Rothera, Antarctica moved its clock 3 hours back in 1976 and left it there — a change of side, not a change of season.
201Vostok, Antarctica moved its clock 7 hours forward in 1994 and left it there — a change of side, not a change of season.
202Easter Island's clock runs 2.3 hours ahead of the sun over it. Noon on the clock is nowhere near noon overhead.
203Dawson's clock runs 2.3 hours ahead of the sun over it. Noon on the clock is nowhere near noon overhead.
204Vostok, Antarctica's clock runs 2.1 hours behind the sun over it. Noon on the clock is nowhere near noon overhead.