intercalary year

1. I think we should do it at least twice in the space of each five-year plan, in the same way as the intercalary month in a lunar leap year turns up once in three years and twice in five.
   我看至少是象闰年、闰月一样，三年一闯，五年再闯，一个五年计划里头至少搞两次。
2. Feb. 29 is an intercalary day; leap year is an intercalary year.
   2月29日是闰日；闰年是有添加日的年份。

noun

1. in the Gregorian calendar: any year divisible by 4 except centenary years divisible by 400

   Synonym:    leap year366 daysbissextile year