No, it’s not a typo; it’s part of a Spanish refrain that goes: no te quites el sayo hasta el 40 de mayo, and here’s why it’s relevant.

First of all, a sayo is a smock, so it translates literally into don’t take your smock off until the 40th of May… or in other words, the 9th of June.

The advice of this very old refrain is: don’t let warm days in May trick you into putting your winter clothes away.

And one look at the weather today, June the 10th – I’m sitting in fog at the moment – demonstrates the wisdom of the saying…

(Feature/Spanish refrains)