DEFINITION:
Standing Still. The point in the earth's orbit around the Sun in which the ecliptic reaches its maximum obliquity.
The Summer Solstice occurs annually around June 22, when the Sun enters Cancer at 23.5 degrees N declination, highest overhead in the northern hemisphere. The longest day of the year.
The Winter Solstice occurs annually around December 22, when the Sun enters Capricorn at 23.5 degrees S declination, its lowest point in the northern hemisphere. The shortest day of the year.