August 23 is a significant date in the lunar calendar, particularly in Vietnam. In 2026, this day corresponds to Kỷ Tỵ, which is the 11th day of the 7th month in the lunar calendar. Many Vietnamese people regard this day with caution, believing it is not a favorable time for important undertakings.

According to traditional beliefs, today is referred to as Đạo Tặc, which is considered an unlucky day. It is commonly advised against embarking on new journeys or making significant decisions, as it is thought that starting on this day could lead to misfortune or loss.

From a seasonal perspective, August 23 also marks the beginning of the Xử Thử period, the 14th of the 24 solar terms in the year. This transition follows the Lập Thu, which began on August 7, and signifies the end of the hot summer days. The Xử Thử period is characterized by the onset of cooler weather, indicating the shift from summer to autumn.

In 2026, Xử Thử officially starts today and lasts until September 7, when the Bạch Lộ period begins. The term Xử Thử translates to "rainy season," symbolizing the end of the oppressive heat and the beginning of more pleasant weather.

Understanding these cultural and seasonal significances can help individuals navigate their plans and activities on this day, reflecting the deep-rooted traditions that influence Vietnamese society.