New Year's Day

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun January 1, the first day of the year, celebrated as a holiday in many countries.

from the GNU version of the Collaborative International Dictionary of English.

• the first day of a calendar year; the first day of January. Often colloquially abbreviated to New year's or new year.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A legal holiday in many countries to welcome the New Year of the Gregorian calendar on January 1.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the first day of the year