It always seems to happen so quickly.
We go in Northern Ireland from having huge amounts of daylight, day after day, in the period from May to July to, suddenly, the autumnal equinox.
It was the autumn equinox yesterday, September 21, when there is an equal amount of daylight and night-time — 12 hours of each.
It seems like only a few weeks ago we were in those super long days in the period around the summer solstice, on June 21, when daylight is bursting through our curtains not long after 4am (even when you have blackout curtains). Now we find that we are already entering the darkest six months of the year.
From now until March 21 there will be more darkness each day than there is daylight — a prospect that always makes me feel gloomy at this time of year.
The long haul of many months of dark winter days stretches ahead of us.
However, there is respite on December 21.
That is the wonderful point in the calendar that you know that the very worst is over and that the light is slowly returning and then, with it, the joy of spring.
How strange it must be to live around the equator and never have this constantly shifting proportion of daylight to night-time.
Instead, day after day, month after month, decade after decade, the sun rises and falls at the same time, with exactly half of any 24 hours darkness, and exactly half daylight.
• Ben Lowry (@BenLowry2) is News Letter deputy editor