Forwards, backwards, all points in between

Arriving before you've left? We unravel the mysteries of the world's time zones

* Michael Jackson planned to play two concerts at midnight on Millennium Eve, one in Sydney and one in Honolulu, made possible by the different time zones - Honolulu is 20 hours behind Sydney. He cancelled both shows.

* Michael Jackson planned to play two concerts at midnight on Millennium Eve, one in Sydney and one in Honolulu, made possible by the different time zones - Honolulu is 20 hours behind Sydney. He cancelled both shows.

* If you were standing on Russia's Big Diomede Island on a Monday at 9am, two miles east on Alaska's Little Diomede, it would be noon - on Sunday.

* China is the largest country to observe a single time zone, meaning that the sun can rise at 5am and 9am depending on which part of the country you are in.

* Nepal is five-and-three quarter hours ahead of GMT.

* Crossing the border directly south from Chetumal in Mexico to Belize, between April and October, you must wind back your watch by one hour, as Belize does not observe DST, whereas Chetumal does.

* Ships crossing the International Date Line repeat the day if travelling eastwards, and skip a day if travelling to the west. People flying east over the Date Line do not have to advance their watches, but instead skip a day of the calendar - and repeat one if travelling west.

* If you fly from Amsterdam to London, you could arrive before the time that you left.

* Newfoundland, Canada, adopts "Newfie Time", three and a half hours behind GMT, and is the earliest North American continental time zone. Other half-hour offsets can be found throughout India, Afghanistan (Kabul), Iran (Tehran), Burma (Rangoon), Lord Howe Island, Pitcairn Island, Norfolk Island and the Central Standard Time zone of Australia (Darwin and Adelaide).

* Russia spans 11 time zones ranging from two to 12 hours ahead of GMT.

* The continental US falls into four time zones: Eastern Standard, Central Standard, Mountain Standard and Pacific Standard. States can choose not to follow DST if they straddle or border time zones. The only mainland state that does not observe daylight saving time is Arizona, which remains in the Mountain Time Zone year round, seven hours behind Greenwich Mean Time (GMT).

* Hawaii has its own time zone, Hawaiian Standard Time, which runs three hours behind Pacific Standard Time and 10 hours behind GMT. Alaska also has its own zone, nine hours behind GMT.

* Twelve of the 13 Canadian provinces and territories put their clocks forward in April, but Saskatchewan remains in the Central Time Zone, six hours behind GMT.

* Portugal is the only continental European country on the same time as the British Isles. Iceland, Morocco, the Gambia, Guinea, the Ivory Coast, Liberia, Mali, Senegal and Sierra Leone are all also on the same time.

* In 1996 the member countries of the European Union agreed to synchronise advancing their clocks by one hour on the last Sunday of March to mark the beginning of summer time. All EU countries put their clocks back on the same Sunday in October.

* In the United States, the Uniform Time Act, passed by Congress in 1966, decrees that daylight saving time should be adopted by all states from the last Sunday in April to the last Sunday in October. This was moved to the first Sunday in April in 1987.