In ancient Rome, March was called Martius. It was named after the war god (Mars) and the Romans thought that it was a lucky time to begin a war. Before Julius Caesar's calendar reform, March was the first month of the year in the Roman calendar, as the winter was considered to be a monthless period.
March is one of seven months to have 31 days. March begins on the same day of the week as February in common years and November every year, as each other's first days are exactly 4 weeks (28 days) and 35 weeks (245 days) apart respectively. March ends on the same day of the week as June every year, as each other's last days are exactly 13 weeks (91 days) apart.
In common years, March starts on the same day of the week as June of the previous year, and in leap years, September and December of the previous year. In common years, March finishes on the same day of the week as September of the previous year, and in leap years, April and December of the previous year.
In years immediately before common years, March starts on the same day of the week as August of the following year, and in years immediately before leap years, May of the following year. In years immediately before common years, March finishes on the same day of the week as August and November of the following year, and in years immediately before leap years, May of the following year.
In leap years, the day before March 1 is February 29. This determines the position of each day of the year from there on. As an example, March 1 is usually the 60th day of the year, but in a leap year is the 61st day.
In terms of seasons, March is one of two months to have an equinox (the other is September, its seasonal equivalent in both hemispheres), with daylight and darkness of roughly the same number of hours, halfway between the December and June solstices. In the Northern Hemisphere, spring starts in this month, while it is autumn in the Southern Hemisphere. The official start of either season is March 1, though the equinox can fall on March 20 or 21, occasionally on March 19. The northern spring equinox marks the start of the Iranian New Year and Baha'i New Year. It is from the March 21 date that Easter's date is calculated, on the Sunday after the first full moon in spring, meaning it can fall between March 22 and April 25 in Western Christianity.