Equinoxes and solstices are a result of two things: Earth’s tilt and its orbit around the Sun. Solstice, the term comes from the Latin words sol and sistere , meaning “Sun” and “to stand still” . Initially, the naming arose from observations of how the Sun’s apparent path across the sky changes slightly from one day to the next, which is caused by the same process as the subsolar point's movement described above. In the months leading up to the June solstice, the position of sunrise and sunset creeps northward. On the day of the solstice, it reaches its northernmost point. After that, the daily path of the Sun across the sky begins to creep southward again. The summer solstice or estival solstice occurs when one of Earth 's poles has its maximum tilt toward the Sun . It happens twice yearly, once in each hemisphere ( Northern and Southern ). Compare...