By Juliet Hindell in Tokyo

Monday is a national holiday in Japan but some people may not realise and go to work.

The holiday has been moved from 15 January to be the first of Japan's new Happy Mondays.

Two years ago the government introduced legislation to change two fixed holidays so that Japan could have more three-day weekends

The thinking was to encourage people to travel in Japan and spend more money.

But calendar and diary companies in Japan have been inundated with calls from irate customers in recent weeks.

Old calendar

They complain that the calendars have got the dates of national holidays wrong, moving the coming-of-age day from 15 January to 10 January. In fact, the calendars are correct.

The holiday when the country's young people celebrate turning 20 has been moved, the first of the so-called Happy Mondays.

Two years ago the government introduced legislation so that holidays would always fall on Mondays and give the nation more long weekends.

But many people in Japan have forgotten about the changes and have made plans according to the old calendar.

The Happy Mondays were introduced in part to give a boost to the economy.

No plans

Estimates say that the new three-day weekends could encourage the Japanese to spend an extra $80bn. It was hoped that many would use the days off to travel in Japan.

But this year at least travel companies report no significant increase in domestic bookings. Instead they say they have seen a sharp rise in overseas holidays as this holiday is close to others in early January.

Surveys have also shown that most people have no particular plans for Monday - that is of course if they are aware it is a day off.

So remember, if you are in Japan on Monday, you should not go to work. The next new holiday is the second Monday in October.