Is the solar term in off-year an important festival?

Off-year is not a solar term. Due to local customs, the days called off-year are different. During the off-year period, the main folk activities include sweeping dust and offering sacrifices to stoves. The traditional off-year (dust-sweeping day) is the 24th day of the twelfth lunar month. In most parts of the south, the ancient tradition of celebrating the New Year on the 24th of the twelfth lunar month is still maintained. Since the middle and late Qing Dynasty, the emperor's family held a ceremony to worship heaven on the 23rd of the twelfth lunar month. In order to "save money", they also worshipped the kitchen god, so people in the northern region followed suit and celebrated the New Year on the 23rd of the twelfth lunar month one day earlier.