八月十五的英文是August 15th，这是中秋节的日子。

August 15th holds significant importance in many cultures, most notably as the date of the Mid-Autumn Festival, a traditional celebration deeply rooted in Chinese culture. This festival, also known as the Moon Festival, is a time when families gather to admire the full moon, enjoy mooncakes, and celebrate the harvest. The full moon on this day is believed to be the brightest and most beautiful of the year, symbolizing completeness and unity. Mooncakes, round pastries filled with various sweet or savory fillings, are the centerpiece of the festival's culinary traditions, often shared among family and friends as a symbol of togetherness. The Mid-Autumn Festival is not only a time for feasting and merrymaking but also for reflecting on the past year and giving thanks for blessings received. It is a poignant reminder of the importance of family bonds and the beauty of nature, all centered around the luminous symbol of the full moon that illuminates the night sky on August 15th.