The winter solstice is a vampire's delight. No other night is longer and no day shorter. But sorry blood-suckers, it also means the subsequent days get longer.

This year's winter solstice will occur at 12:30 a.m. Dec. 22. At that moment, the sun will be directly overhead at 23.5 degrees south latitude, and the Earth's axial tilt will be as far from the sun as possible.

BLOG: What is the Summer Solstice?

When the celestial fireball finally makes its appearance in the northern hemisphere it keeps a low profile. On the winter solstice the sun follows the lowest path of the year in the sky of the northern hemisphere.

The Washington Post provided some details about the solstice sun over the United States' capital:

• The sun is above the horizon for approximately 9 hours, 26 minutes
• Sunrise occurs at 7:24 a.m. and sunset at 4:50 p.m.
• The sun angle at solar noon (12:07 p.m.) reaches its minimum height of 27.7º above the horizon (compared to 74.6º above the horizon on June 21)
• The sun rises at its southeasternmost point and sets at its southwesternmost point along the horizon (120º and 240º from due north, respectively)

For modern city-dwellers, the solstice is little more than a curiosity, but in ancient times it was of vital importance.

In the northern hemisphere, knowing when the dark days of winter would start to lengthen could give hope to people trying to make the harvest of the previous year stave off starvation for a few more months.

The day was so important, that some of humanity's earliest monumental structures were aligned with the rising or setting of the sun on the winter solstice. Stonehenge in England, for example, is lined up with the winter solstice.

BLOG: Bones Hint at Stonehenge Solstice Feast

Festivals both ancient and modern marked the winter solstice.

The Romans celebrated Saturnalia around the time of the solstice with revelry and a social switcheroo in which masters served the slaves.

Further north, Germanic and Norse tribes celebrated Yule by burning a massive log in honor of Thor, a tradition some still observe.

The modern Christian holiday of Christmas occurs near the winter solstice, and some have suggested that assigning December 25th as the birth of Jesus of Nazareth related to ancient celebrations of that day, such as the Roman Sol Invictus, or Invincible Sun, festival.

IMAGES:

Winter solstice dawn over Llanrug. (Eric Jones, Wikimedia Commons)

Illumination of Earth by Sun on the day of winter solstice on northern hemisphere. (Przemyslaw Idzkiewicz, Wikimedia Commons)

Sunrise between the stones at Stonehenge on the Winter Solstice, Dec. 22, 1985. (Mark Grant, Wikimedia Commons)