Each year, at a precise and unremarkable moment, the Earth arrives at a point of cosmic balance — the autumn equinox — when neither hemisphere leans toward the Sun and day and night hold equal measure across the world. This year, that threshold falls at 01:06 BST on 23 September 2026, an instant invisible to the eye yet felt across cultures and centuries. It is not a switch but a turning, the beginning of a slow tilting away from light that will deepen through the months ahead.