New Year's Day on January 1st marks the start of the year according to the Gregorian calendar, which was introduced by Pope Gregory XIII in 1582.

This calendar is now internationally accepted for civil matters and is the most widely used. In the U.S., Europe, and many other parts of the world, January 1st is a public holiday.

Celebrations often include midnight countdowns, firework displays, and making New Year's resolutions. Historically, Julius Caesar was the first to declare January 1st as New Year's Day in honor of Janus, the Roman god of doors and gates, back in 45 BCE.

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Don’t forget that the New Year isn't universally celebrated on January 1st!

Here are a few examples:

• Lunar New Year: Often falling between January 21 and February 20, this event is based on the lunar calendar. It's a major celebration in countries like China, Vietnam, and South Korea. In China, it's known as the Spring Festival and is the most significant annual holiday.

• Rosh Hashanah: This is the Jewish New Year, based on the Hebrew calendar. It usually occurs in September or October and is celebrated over two days with prayers and festive meals.

• Diwali: Though not technically a New Year, the Hindu festival of Diwali marks a new beginning and is often considered a fresh start. It usually falls between October and November.

• Islamic New Year: Known as Hijri or the Arabic New Year, this is based on the Islamic lunar calendar. The date changes yearly, shifting approximately 11 days earlier each year according to the Gregorian calendar.

Each of these New Year celebrations has its own unique history, traditions, and significance, making the concept of a "New Year" quite diverse globally.