It was announced today that the UK will transfer sovereignty of the British Indian Ocean Territory to Mauritius. Assuming this happens before March, this means when the sun sets on the Pitcairn Islands (18:50 Local time: UTC-8, 02:50 London time: UTC), the sun will have set on all British territory for the first time in over 200 years.
This the sunlight at that time is shown on the map above, when the sun is set on Pitcairn, there’s still around an hour until it rises in Akrotiri and Dhekelia, meanwhile as it’s just after the spring equinox, the sun will have set over the south pole beginning it’s 6 month long night, and therefore setting on British Antarctic Territory. —reddit