noun
Standard modern name for the eighth month of the Gregorian calendar.
八月はとても暑いです。
August is very hot.
彼の誕生日は八月十五日です。
His birthday is August 15th.
noun
eighth month of the lunar calendar
Historical or traditional use; refers to the eighth month in the old lunisolar calendar, roughly corresponding to September in the modern calendar.
旧暦の八月は、今の九月ごろにあたります。
The eighth month of the old lunar calendar corresponds to around September now.