Kyoto's cherry-blossom record stretches back to 812, and the earliest full-bloom date in all those centuries was March 27 in 1409 until the flowers reached full bloom a day sooner in 2021 — a record pieced together from chronicles and diaries kept by emperors, aristocrats, governors and monks.

Kyoto's cherry-blossom record stretches back to 812, and the earliest full-bloom date in all those centuries was March 27 in 1409 until the flowers reached full bloom a day sooner in 2021 — a record pieced together from chronicles and diaries kept by emperors, aristocrats, governors and monks.

In the year 812, someone in Kyoto wrote down the date the cherry trees came into full bloom. They kept doing it, on and off, for the next twelve centuries. What survives is one of the longest continuous records of a natural event anywhere on Earth. It runs from the imperial court of the early ninth century straight through to the smartphone era. The record reaches back to 812 CE, when Japan’s aristocracy held flower-viewing banquets and noted, y…