Aprilis – April (warmed by the Sun)
Maius – May (named after the goddess Maya)
Junius – June (named after the goddess Juno).
Quintflis – fifth (from 44 BC. Julius – July, in honor of Julius Caesar)
Sextllis – sixth (from 8 AD Augustus – August, in honor of the Roman emperor Augustus)
September – September (seventh)
October – October (eighth)
November – November (ninth)
December – December (tenth)
Januarius – January (named after the god Janus, the name of God is associated with the words janus covered passage and janua door; god of doors, entrance and exit, every beginning).
Februarius – February (month of purifications, from februare to cleanse, to make an atoning sacrifice at the end of the year).
Julius Caesar in 46 BC e., on the advice of the Egyptian astronomer Sosigenes, carried out a radical reform of the calendar according to the model adopted in Egypt. A four-year solar cycle was established (365 + 365 + 365 + 366 = 1461 days) with unequal lengths of months, still accepted today: 30 days (April, June, September, November) and 31 days (January, March, May, July, August, October, December), in February – 28 days for three years and 29 days for the fourth year. Caesar moved the beginning of the year to the first of January, since on this day the consuls took office and the Roman economic year began.
The Gregorian calendar, introduced in 1582 under Pope Gregory XIII, corrected most of the remaining differences between the Julian calendar and the solar year.
Several contemporary proposals have been put forward to reform the modern calendar, such as the Universal Calendar, the International Fixed Calendar, the Holocene Calendar, and the Hanke–Henry Permanent Calendar. Such ideas are discussed from time to time, but they fail to gain popularity due to the loss of continuity and massive upheaval that their implementation would entail, as well as their impact on the cycles of religious activity.
Other cultures celebrate their traditional or religious New Year according to their customs, usually (though not always) as they use a lunar or lunisolar calendar. Well-known examples include Chinese New Year, Islamic New Year, Tamil New Year (Puthandu) and Jewish New Year. India, Nepal and other countries also celebrate New Year according to their own calendars, which vary according to the Gregorian calendar.