Today is a Japanese public holiday called 「敬老の日」. In English, it means “Respect For Elders Day“. Sometimes it’s called “Grandparents Day“.
It occurs on the third Monday of September. (When I first came to Japan, this holiday was on September 15th, but was changed around fifteen years ago).
And, on September 23rd is 「秋分の日」 (Autumn Equinox). In Japan, the Spring and Autumn equinoxes are days to pay a visit to the family grave-site.
So, on years like this year…where these two holidays fall close together, the day between them becomes a “filler holiday” to make a series of consecutive days off similar to Japan’s “Golden Week” in Spring.
Golden Week is an annual occurrence…but a long holiday period only occurs occasionally in September. When it does, it’s called “Silver Week“.
Right now, Japan is in Silver Week. Most people have holiday from last Saturday until Wednesday.
The next Silver Week won’t occur until 2026!