The month of March used to mark the beginning of the New Year, and in many religious traditions, it still marks the beginning of the spiritual new year.
The month of March gets its name from the Roman God of War, the planet Mars. Mars was not only a defensive warrior, he was also a god of aggression, and taking action, so he is also associated with the beginnings of things, so when his month came 'round, that was the beginning of the new year.
Also in the month of March, we have the first day of Spring, which is known technically as the Vernal Equinox. Equinox is the point where it appears to us that the Sun comes to the Celestial Equator, and begins to move into the Northern Celestial Hemisphere. This marks the point in the cycle of the year when, in the Norther Hemisphere, we begin to have greater sunlight.
This time of year is also the 'trigger' for when it's appropriate to celebrate the Spring festivals of renewal, including the Passover, the renewal of fire, or the Easter Festival.
We can still 'hear' March as the beginning of the new year when we listen to the names of the calendar months that are still in use. September is the seventh month from March; October is the eighth month; November the ninth month from March; and December is the tenth month.
The other interesting thing about March is that it comes in like a lion and goes out like a lamb. This isn't just a reference to the weather; it's a reference to the stars that are rising and setting at this time. The constellation Leo, the Lion, is rising up in the East at sunset, while the stars of Aries, the Ram or Lamb, are starting to be swallowed up in the light of the Sun looking West at sunset.
By month's end, the stars of Aries will 'go out' with the Sun, so we can truly say the March brings in the Lion, and goes out with the lamb.