元旦，即公历的1月1日，是世界多数国家通称的“新年”。元，谓“始”，凡数之始称为“元”；旦，谓“日”；“元旦”意即“初始之日”。中国历史上的“元旦”之名称指的是夏历（阴历，又称农历）正月初一，有现存文献记载的“元旦”一词最早出现于《晋书》。
从汉武帝起，规定孟喜月（元月）为正月，把孟喜月的第一天（夏历的正月初一）称为元旦，一直沿用到清朝末年。
1949年9月27日，第一届中国人民政治协商会议，决定采用世界通用的公元纪年法，即我们所说的阳历。元旦，指西元纪年的岁首第一天。
New Year's Day, January 1 of the Gregorian calendar, is the "New Year" known to most countries in the world.
Yuan, that is, "beginning", where the beginning of the number is called "yuan"; Dan, that is "day"; "New Year's Day" means "the initial day."
The name "New Year's Day" in Chinese history refers to the first day of the first month of the summer calendar(lunar calendar, also known as the lunar calendar). The word "New Year's Day" recorded in existing documents first appeared in the "Jin Shu".
From Han Wudi, it was stipulated that Mengxiyue(January) was the first month, and Mengxiyue's first day(the first day of the first month of the summer calendar) was called New Year's Day and was used until the end of the Qing Dynasty.
On September 27, 1949, the first session of the Chinese People's Political Consultative Conference decided to adopt the universal method of the AD, which is what we call the solar calendar.
New Year's Day refers to the first day of the year of the Western Yuan Dynasty.