I wasn’t too sure when Michaelmas was – bar that it is in the Autumn. We looked it up when we got home.
It seems Michaelmas, the feast of Saint Michael, is on 29 September and is regarded as the start of autumn.
Old Michaelmas Day is in October. The story is that after then brambles don’t taste so good because the Devil pisses on them.
Whatever the reason they do tend to be more bitter later in the season.
Of course, in Scotland we refer to both the plant and the fruit as brambles.