kuánian shì shí èr yuè sānshiyi rì wànshang yingjiē xinnián, yuàndan shì yī yuè yī rì

跨年是 12 月 31 日晚上迎接新年，元旦是 1 月 1 日。

Crossing over the year is on the evening of December 31st to welcome the new year, while New Year's Day is January 1st.