Hi, Maciej. This week you see many photo of beautiful moon by PENTAX users. I'd like to explain about "中秋の月”. ポーランドのマチェイさん、美しい月の写真が次々アップされていますが”中秋の名月”をウィキペディアを引用してちょっとご紹介。
"中秋”means "Mid-Autumn". The Mid-Autumn Festival falls on the 15th day of the 8th lunar month of the Chinese calendar (usually around mid- or late-September in the Gregorian calendar). This is the ideal time, when the moon is at its fullest and brightest, to celebrate the abundance of the summer's harvest.