noun
middle ten days of a month; 11th to 20th of a month
Calendar term referring roughly and usually specifically to days 11 through 20 of a month; often used after a month name, as in 4月中旬.
桜は4月中旬まで楽しめます。
You can enjoy the cherry blossoms until mid-April.
結
The results will be announced in the middle of next month.