News Item

The Winter solstice

The Sun reaches its furthest point south today, 21 December.

At 1044 UTC today, 21 December, the Sun reaches its furthest southern extremity of 23ยบ26.1'. Astronomically, this - the shortest day - is the start of Winter but, meteorologically, Winter comprises the months of December, January and February.

The Sun will return to the northern hemisphere at the Vernal equinox - 1028 UTC on 20 March 2017. It will reach the furthest north at the Summer solstice - 0424 UTC on 21 June 2017.

This year is a particularly long one, including both a leap day (29 February) and a leap second, due after 23:59:59 on 31 December. The leap day accounts for the Earth taking ~365.25 days to orbit the Sun - this keeps the seasons consistent year-on-year forever. The leap second accounts for the slowing of Earth's own rotation compared with International Atomic Time (TAI)'s atomic standard, to which it was synchronised in 1972. On 1 January 2017, the difference between Coordinated Universal Time (UTC) and TAI will be 36 seconds.

Further details from the link below . .

  • 20 December 2016
  • RIN

Contact Us

The Royal Institute of Navigation
1 Kensington Gore

+44 (0)20 7591 3134

E-Mail Communication

The Royal Institute of Navigation periodically sends out email updates to its membership and those who have subscribed to events and conferences run by the RIN. In doing so, the RIN takes all reasonable precautions to ensure that the emails are only sent to those who have requested them, and that no third party can make unauthorised use of any email address to send out mailings.If you receive unsolicited mail from any address then please inform us at and we will take appropriate action.

Join the RIN

You can apply for any category of RIN membership by completing the online membership application form and paying using our secure credit/debit card payment system.

Join Now