Today, October 9, is the last day of the lunar month of Đinh Dậu in the year of Bính Ngọ. According to the lunar calendar, today is the 29th day of the 8th month, known as Bính Thìn. As we transition to tomorrow, the Vietnamese will officially enter the lunar month of Mậu Tuất.

The lunar month currently being observed, which is the 8th month, started on September 11 and concludes today. This month has 29 days, and the arrival of the new month is significant in Vietnamese culture.

From a seasonal perspective, today marks the second day of the Hàn Lộ period, which is the 17th of the 24 solar terms in the year. This period, which began on October 8, will last until October 22, followed by the Sương Giáng period starting on October 23. Hàn Lộ translates to 'cooling,' indicating a shift in the weather as the sun moves closer to the southern hemisphere, resulting in cooler temperatures in the northern hemisphere.

Additionally, October 9 is recognized worldwide as World Post Day, commemorating the establishment of the Universal Postal Union (UPU) in Bern, Switzerland, on this day in 1874. The UPU was founded to facilitate international postal services, and Vietnam became a member in 1976, contributing to the development of postal services in the country.

As the lunar calendar plays a vital role in Vietnamese culture, the transition to the new month is a time for reflection and preparation for the upcoming lunar events.