The calendar that has January 1st as its first day of the year is known as the Gregorian Calendar.
The Gregorian Calendar:
- Has January 1st as its new year.
- Is based on the Julian calendar.
- Is used by most of the world.
The Gregorian Calendar was instituted by the Vatican under Pope Gregory XIII and because of the dominance of Christianity at the time, it came to be used by most of the world.
In conclusion, the answer is the Gregorian Calendar.
Find out more about the Gregorian Calendar at https://brainly.com/question/898496.
