New Year is perhaps the oldest and most widely celebrated event in the world. Celebrating the New Year on the 1st of January is a recent trend.

History of New Year
According to history, New Years Day was celebrated at least as far back as 2000BC. Although it was probably celebrated earlier than that, this is thewhen actual records of the celebrations occur. These records show thatthe Babylonians, from whom we get so many traditions concerning everything from the way we do math to how we keep track of the stars, celebrated New Years Day on the day when the moon was just visible after having gone dark after the vernal (spring ) equinox. This would have put New Years Day for the Ancient Babylonians near the end of March or possibly the beginning of April, depending on the year. The celebration was tied not just to the new year, but also to the planting of the crops and the earth coming back to life after winter.Some of the traditions we associate with New Years Day originate with the Babylonians. For example, the tradition of New Years resolutions is thought to have begun at this time. History tells us that the custom of making a New Year’s resolution began with the Babylonian custom of returning something that they had borrowed from a neighbor or friend on New Year’s Day. The Romans would carry on the custom of the resolution by promising themselves to ask for forgiveness from an enemy or someone they had wronged the previous year.

New Year Eve

Here are some major celebrations.

In Brazil, two major cities, Rio de Janeiro and São Paulo, celebrate the New Year. Most famously in Rio de Janeiro which occurs in Copacabana beach, drawing 1.5 to 2.5 million people.

In Australia, celebrations are held around the nation, especially in Sydney, where one of the world's largest fireworks displays draws 1 to 1.5 million people to the harbour. Australia is one of the first countries in the world to celebrate the new year.

In New York City, the world famous 1,070-pound, 6-foot-diameter Waterford crystal ball located high above Times Square is lowered starting at 11:59:00 p.m., or the last minute of the year, and reaches the bottom of its tower at the stroke of midnight. It is sometimes referred to as "the big apple" like the city itself; the custom derives from the time signal that used to be given at noon in harbors.

Also people send new year greeting cards, new year ecards and gift to other people to celebrate new year.

here is the wiki article about new year