June 21st was the summer solstice, the longest day of the year.
夏 = summer
至 = arrive
Whilst not an official holiday in Japan, it is nevertheless important as it is one of the “24 solar terms”.
These 24 solar terms are mini seasons dating from ancient times, which reference the weather, agriculture, and (as the name suggests) the movements of the sun. You can find out more about them here.
Calligraphy by Vicky 