The two points on the ecliptic where the Sun is farthest from the celestial equator are called the solstices.

* Summer Solstice: The Sun reaches its most northerly declination (farthest north of the celestial equator), around June 21st.

* Winter Solstice: The Sun reaches its most southerly declination (farthest south of the celestial equator), around December 21st.

These points mark the beginning of summer and winter in the Northern Hemisphere, respectively.