Definition of

Solstice

Solstice

When the Earth is the most tilted away or towards the Sun.

The days when this happens are called:

• Summer solstice (the longest daytime of the year)
• Winter solstice (the shortest daytime of the year)

Solstice happens around June 21 and around December 21 each year.

See this animation for why it happens:

../measure/images/earth.js
See: Equinox