December 21, the shortest day of the year : Understanding the Winter Solstice


Guwahati: Each year, there’s one day in the winter when we have the shortest amount of daylight and the longest amount of night-time – which falls just before Christmas.

And this year the shortest day of the year – in the northern hemisphere that is – is today, December 21.

Monday, December 21 is a day of great events, as it marks the Winter Solstice. Also known as December solstice, hiemal solstice, or hibernal solstice, the event takes place when one of the Earth’s pole is tilted away from the sun at its maximum distance.

The month of December has hosted various celestial events, and two of them are occurring together on December 21. Apart from the winter solstice, the day will also be remembered for the great conjunction, when Jupiter and Saturn will display a visual overlap in the night sky.

The number of daylight hours on the shortest day amounts to 7 hours, 49 minutes and 42 seconds – some 8 hours, 48 minutes, and 38 seconds shorter than the summer solstice, when daylight hours are at a maximum.

However it’s not all bad news – as the days do start getting a little longer and the nights a little shorter from then on, not that you will notice much difference for a few months. The astronomical winter lasts until the Spring Equinox, which next year will be on March 20 2021 – while the clocks go forward once again on Sunday March 28 2021, once again ushering in longer days and shorter nights.