January and February were the last two months to be added to the calendar, since the Romans originally considered winter a monthless period. Although March was originally the first month, January usurped that position because that was when consuls were usually chosen.
The first day of the month is known as New Year's Day. The coming of age day in Japan since 1948 is a national holiday on which the nation celebrates those who turn 20 years of age. The day used to be January 15 until the year 1999. The day was moved by the Japanese government in an attempt to lift the economy by increasing consecutive holidays.