Why is the Lantern Festival in Nanjing?

Why is the Lantern Festival in Nanjing? In this area around Nanjing, there are many off-year holidays, some on the fifteenth day of the first month, some on the fifth day of the first month, and some both.

According to a personal story, the thing is this:

Emperor Yongle successfully entered Beijing, restored the old Taizu system and abolished a series of benevolent policies in Wen Jian. On the first Lantern Festival after Jingnan, people commemorated Emperor Wen Jian in succession, and held various cultural activities in the city to commemorate him, such as the Lantern Festival, which was a grand occasion like the Spring Festival, so Nanjing people took the Lantern Festival as a small year from now on.

There is also this custom around Nanjing, influenced by Nanjing.

However, there are two bugs in this explanation.

First, when I was studying in Yunnan, I asked many classmates. Their hometown also celebrated the Spring Festival around the Lantern Festival, on the 15th and 16th of the first month. Immigrants played an important role in the formation of Han customs in Yunnan in the early Ming Dynasty. A large number of residents from Nanjing, the capital at that time (and the surrounding areas of South Zhili), brought the folk customs of Nanjing here, merged with the local folk customs and folk customs of other provinces, and formed a unique folk custom in Yunnan. In this way, the folk customs of the fifteenth or sixteenth year of the first month should have been customized as early as Emperor Hongwu, and it is impossible to be associated with Yongle Jingnan. (Of course, it is also possible that this folk custom in Yunnan has other sources, but it is so similar to the folk custom in Nanjing and different from other places. I think it can be written here as a talk. )

Secondly, the Qinhuai Lantern Festival in Nanjing can be said to be very famous, but not only in the Ming Dynasty. As early as the Six Dynasties and the Southern Qi Dynasty, the Lantern Festival was recorded. During the Southern Tang Dynasty, Qinhuai Lantern Festival was an important festival in Nanjing. Therefore, after Nanjing, it is untenable for Nanjing people to hold the Qinhuai Lantern Festival to commemorate Wen Jian.

In addition, there is a saying in Beijing that the Lantern Festival is a small year (obviously it focuses on "the year has passed", while the small year on the 23rd of the twelfth lunar month focuses on the New Year and reaches its climax). Personally, I think it may be related to immigrants after Jingnan, but there is no evidence. Let's just write here as a chat.

As an ordinary citizen of Nanjing, I know so little about this question. Wait for the Great God to answer it.