Ireland, Britain and the United States · October 31, 2026
October 31 — the eve of All Hallows, and the oldest surviving night for costumes.
Halloween is a braid of three things rather than one. The oldest strand is Samhain, the Gaelic festival at the end of the harvest, when the year turned toward winter and the boundary between this world and the other was thought to thin. The second is Christian: in the eighth and ninth centuries the Church set All Saints’ Day on November 1 and All Souls’ on the 2nd, and the evening before became All Hallows’ Eve — which is all the word Halloween is. The third is Irish and Scottish emigration in the nineteenth century, which carried guising, turnip lanterns and door-to-door rhymes to America, where the pumpkin replaced the turnip because pumpkins were larger and easier to carve. Trick-or-treating as we know it is surprisingly recent: it spread across North America in the 1930s and 40s.
It is the one night of the year when children are supposed to be out after dark, in disguise, knocking on the doors of people they do not know — and the whole street agrees to it. Almost nothing else in modern childhood works like that. The costumes matter more than the sweets: for one evening a child chooses who they are and everybody plays along.
Carve something on a fixed evening every year and photograph the child beside it, at the same age each time. And let them choose the costume entirely, even when the choice is baffling.