Hi, its Lin and I'd like to start off with a new word of Mandarin that you can use in your daily life.
圣(shèng) 诞(dàn) 快(kuài) 乐(lè)！ =Marry Chrismas 元(yuán) 旦(dàn) 快(kuài)乐(lè)！=Happy New Year's Day!
Now the Chrismas and the new year is coming and you may say 圣(shèng) 诞(dàn) 快(kuài) 乐(lè)！and 元(yuán) 旦(dàn) 快(kuài)乐(lè) to your friends in Chinese!
元(yuán) 旦(dàn) is a traditional Chinese holiday, means “the first of the year”. Long Long ago, the date of the holiday changed a lot as we use lunar calendar and have different dynasty. Until 1949.Sep.27th, the date of 元(yuán) 旦(dàn) is established by the government according to the calendar which is popular around world.
However, Spring Festival is the most important traditional holiday to Chinese people, therefore, we use “新(xīn)年(nián) 快(kuài)乐(lè)” (Happy New Year)during Spring Festival instead of Jan.1st.