Generally speaking, the Ox day during the doyo indicates the summer one, but as the doyo comes around four times in a year, the day also comes around several times in a year.
一般には土用の丑の日といえば夏を指すが、土用は春、夏、秋、冬の年4回あり、土用の丑の日は年に数回ある事になる。