Google wore her autumn with a new Doodle that reminds us of the day and the fact of the autumn equinox. On 11: 20 this morning Wednesday September 23 (Greek time), the autumn equinox occurs in the northern hemisphere. 
The northern hemisphere belongs to Greece, and the autumn equinox marks the astronomical start of this autumn.
In the southern hemisphere spring begins.
Equinox occurs twice a year when the Earth's axis is aligned parallel and at right angles to the axis of the sun.
At this moment the Sun is in line with the vertical equator of the earth, resulting in night and day having equal duration at any point on the Earth's surface.
Equinox occurs around 20 March and September 22. At this point the deviation of the earth's axis is zero to the sun.
Google would not let it go unnoticed, so if you look today on the homepage of the search engine you will see the corresponding Doodle.
With information from WikiPedia.
Dimitris hates Mondays...
