The New Year celebration last from the New Year's Eve to Lantern Festival,which,in lunar calendar,is from the last day of the year to the fifteenth day of January.
in lunar calendar,也可以放到最后
还有我觉得最后一个月,第一个月,不用强调,用一月就能表达清楚意思.
我觉得吧,最通顺的翻译其实是把日期放进括号里.你考虑一下New Year's Eve是不是不用翻译了.元宵节后应该有一个(Jan.15th in Lunar calendar).我觉得这样看上去最好~
改你老师给的答案：The New Year celebration starts on Chinese New Year’s Eve,the last day of the last month in Chinese lunar calendar,and lasts to the Lantern Festival,the 15th day of the first monthin Chinese lunar calendar.