also: ひとのうわさもななじゅうごにち
expression
a wonder lasts but nine days; gossip lasts just 75 days
Proverb meaning that rumors and gossip fade away quickly, typically within about 75 days. Used to comfort someone worried about being talked about.
人の噂も七十五日というから、あまり気にしなくていいよ。
They say gossip lasts only 75 days, so you don't need to worry too much.
A traditional Japanese proverb. The origin is uncertain, but it reflects the folk belief that rumors naturally die down after about 75 days.