Soon it will be the Autumnal Equinox, a phrase I have never heard used outside Japan but as it's one of the national holidays here, it makes it into every calendar there is. For those unsure of the actual nature of an equinox, it's a day that occurs twice a year when night and day are precisely the same length. Twelve hours of daylight and twelve hours of darkness. In Spring it signals the advent of longer evenings and in Autumn it's the bringer of cold mornings and huddling home early.
In Japan though it was one of the few days of rest for the local village monks for one of their roles was always to adjust the clocks. Time in medieval Japan was not measure in the regular way of dividing the day into twenty four hours. This was a European concept and not adopted until contact was established hundreds of years later.
A day in Japan was divided into twelve hours. Six of them for daylight and six of them for darkness. And there lay the problem and the need for constant adjustment. As the period of daylight and darkness varied throughout the year, so the clocks needs moving slightly forward or backwards depending on the annual cycle. Life for the village monk used to be a busy one, rushing to update time pieces everywhere.
You have to wonder though what they do now to keep busy in the modern era of quartz watches and hours that remain an hour irrespective of the time of year.