People in Ethiopia are preparing to celebrate the New Year on 12 September and for them, it will be very special - the start of the year 2000 and the beginning of millennium celebrations.
By Elizabeth Blunt
BBC News, Addis Ababa
But the reason why they are celebrating more than seven years after the rest of the world is rooted in Ethiopian history and in the beliefs of its own Christian Orthodox Church.
Educated Ethiopians live comfortably in two calendars.
It is still 1999 here and the month is Pagume when they speak Amharic - September 2007 when they speak English.
The only thing that ever seems to faze them is the complication caused by the leap years in the two calendars being out of sync.
But even if they are quite at home with the Western calendar, Ethiopians show no sign of wanting to abandon their own.
It is part of their national identity, not to mention allowing their tourist industry to boast that they can offer visitors 13 months of sunshine.
Several major events are planned to celebrate the millennium
The short 13th month is just one of the tell-tale signs that Ethiopians took their calendar from ancient Egypt.
Another is the date of New Year, originally linked to the annual flood which brought new life to the Nile Valley.
But none of this explains why the millennium is seven years late; why Ethiopians think that it is 2000 and not 2007 years since the birth of Christ.
Ahmed Zakaria, professor of history at Addis Ababa University says the reason is that the Roman Church amended their calculation in 500 AD - adjusting it by seven or eight years.
The Patriarch says Ethiopia became isolated from other countries
"So we are seven or eight years later than the Roman calculation, so that's the difference that came in."
The recalculation of the birth of Christ was just the first of a number of changes in the rest of the world which the Ethiopian church ignored.
It is partly because the country was so remote and isolated, but also, says the current patriarch, Abuna Paulos I, because Ethiopian Christians are intensely conservative.
"People are not inclined for any reformations, especially when it comes to religion.
"They are very much loyal - to change one sentence is a betrayal as far as they are concerned.
"So because of this, they have been isolated. They have been loyal to their faith and they have maintained their own traditions."
And so here in Ethiopia it is still 1999, we're all seven years younger, and on the 12 September, the first of Meskeram, we'll finally join the rest of the world.