That's the Metrological Spring... the Astronomical...

season

The next astronomical spring begins on 20 March 2015 and runs until 21 June 2015.

The astronomical calendar determines the seasons due to the 23.5 degree tilt of the Earth's rotational axis in relation to its orbit around the sun. Both equinoxes and solstices are related to the Earth's orbit around the sun.

Earth's axis and seasons Earth's rotational axis and orbit around the sun determine the seasons Solstices and equinoxes are considered to be the astronomical transition points between the seasons and mark key stages in the astronomical cycle of the earth. In a year there are two equinoxes (spring and autumn) and two solstices (summer and winter). The dates of the equinoxes and solstices aren't fixed due to the Earth's elliptical orbit of the sun. The Earth's orbit around the sun means that in early January, the sun is closest (known as perihelion) and in early July it is most distant (aphelion).

Posted By: Pixelman, Mar 6, 11:59:36