According to the Lunar Calendar, from now until 2032, the 12th lunar month will only have 29 days. It will not be until 2033 that people will experience the 30th day of Tet again. The reason for this is because the Lunar Calendar is calculated according to the cycle of the Moon.
Researcher Dang Vu Tuan Son - President of the Vietnam Astronomy and Cosmology Association (VACA) - explained that each full moon cycle to the next full moon is 29.53 days, equivalent to 1 lunar month. Because it is not an even day, the lunar months take turns having 29 or 30 days to compensate to match the cycle.
According to calculations, from now until the end of the year of Tan Hoi (2032), December will always have only 29 days. However, according to Mr. Dang Vu Tuan Son, this does not affect natural conditions or weather.
The expert affirmed: "This is purely a coincidence due to human convention. This has no natural cause, nor is it related to or has any effect on the weather cycle, but is only related to living habits and preparations for Tet."
This year, people across the country will have 9 days off for Tet, starting from January 25 to February 2 (December 26 of the year of Giap Thin to January 5 of the year of At Ty). Although the holiday starts on the 26th of Tet, December only has 29 days, making many people feel that the time to prepare for Tet has been shortened.
Ms. Ha Phuong (31 years old, Nghe An) said: "This December has only 29 days, making me feel like Tet is coming very quickly. Since the beginning of the lunar month, I have been busy going online to buy decorations and Tet gifts to prepare to go back to my hometown and meet both my paternal and maternal families."
Ms. Phuong added that the old saying "30 is not yet Tet" has now become only the 29th of Tet, which makes her children wonder. She had to patiently explain that this is just a metaphor, meaning that if something is not decided until the last minute, it cannot be considered complete.
Because there is no New Year's Eve, all New Year's Eve activities, ancestor worship, and New Year's Eve offerings take place on the 29th of the Lunar New Year.
Ms. Hoang Thi Man (53 years old, Hung Yen) shared: "Every year, my family usually gathers to meet and eat on the 30th of Tet, called the New Year's Eve meal. But this year there is no 30th, so the family gathering schedule has changed to the 29th of Tet.
The offering tray for ancestors and New Year's Eve is also moved to the 29th. My family has a habit of putting the pot of banh chung on the stove, waiting for the cake to cook while waiting for the new year to come. The cake will be immediately put on the New Year's Eve offering tray as soon as it is cooked.
According to Ms. Man, December only has 29 days, so people automatically consider the 29th as the 30th day of Tet. People's eating, drinking, playing, and worshiping activities do not change much. Perhaps it is just that the 30th day is missing, so many people feel that Tet is shorter.
Regarding the weather situation in December and the Lunar New Year 2025, according to the National Center for Hydro-Meteorological Forecasting, in January 2025 (ie December 2024 of the lunar calendar), cold air tends to be more active than in the December 2024 cycle (November of the lunar calendar); there is a high possibility of causing many days of severe cold in the northern provinces, concentrated in the middle of the month.
The South Central region is likely to experience some scattered showers and thunderstorms, with some areas experiencing moderate to heavy rain. The South region may experience some unseasonal rainy days. During thunderstorms, be on guard against the possibility of extreme weather events such as tornadoes, lightning, hail and strong gusts of wind.
With these weather conditions, people in the Northern region are likely to experience a cold Tet, so they should buy and prepare warm clothes and thermal clothing for themselves and their families. Meanwhile, people in the Central and Southern regions need to be on guard against rain and bad weather during Tet 2025.
