Year of the Astounded Beetle
In this year, Brutha was perhaps two or three years old. He remembers that in this year, he first saw an Ephebean coin, a derachmi. As Brutha is described as "a youth" during the events of Small Gods, which we are told took place in the Year of the Notional Serpent, and both years fell in the Century of the Fruitbat, it is possible the two years are separated in the calendar by as little as thirteen or fourteen years and no more than about twenty years? A minor point for those dealing with the Discworld Timeline...
The text, on page 72 of the Corgi paperback, notes that in his own perfectly eidetic memory, Brutha was "one month shy of three years old" when this happened. Vorbis then assesses him as being seventeen or eighteen years old. Therefore the intervening gap between the two named years is, in all probability, no less than fourteen and no more than fifteen years. Brutha adds the incidental detail that this event was on the 3rd Grune. If there was only one month to go before his third birthday, Brutha's birth month would be the one that follows Grune in the Discworld calendar (August).