Tuesday officially marks first day of the winter solstice

(KYMA, KECY/ CNN) - Tuesday is officially winter and supposed to start at precisely 10:59 a.m. EST, meaning 8:59 a.m. MST in Arizona and 7:59 a.m. in California. This otherwise known as the winter solstice.

This will begin the shortest day and longest night of the year in the northern hemisphere in terms of daylight.

Solstice comes from the latin words "sol"-- which means sun and "sistere" which means --to stand still.

The sun will sit at its lowest point in the sky and its noon-time elevation will stay the same for a few days after.

The winter solstice is the source of many custom traditions, symbols and rituals and has played an important role in cultures worldwide from ancient times until today.

After December 21st, the days will grow longer and will continue until the summer solstice in June.