Please see my other comment. I did further research and the problem comes because of drift. The lunar calendar would drift away from astronomical events, and th

Please see my other comment. I did further research and the problem comes because of drift. The lunar calendar would drift away from astronomical events, and this was a known problem, so they would occasionally add a 13th month to a year, but it wasn't done systematically. Also, there have been several attempts among scholars to create conversion tables for dates, and each of them have errors, sometimes up to 4 weeks. So which table did the researchers use? We don't know. And all of the conversion tables have errors, which brings me to my original point: making a claim that "this year is the earliest day of blossoming since the 800s in Japan" is scientifically unverifiable, because we cannot link historical calendar dates to current gregorian dates accurately before 1863, when Japan converted to the gregorian calendar.