leap-year

基本解释

Leap-year proposals are an old folklore tradition that dates back to the 5th century.
闰年求婚是个古老的民俗传统能追溯到五世纪。
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Leap-year day(every four years) and year-end day(every year) would be counted as extra Saturdays.
人们把闰年日（每四年一天）和年末日（每年一天）视为外加的星期六。
I've tested these functions with first, middle& last dates of the next12 months( which includes a leap-year) and they seemed to return the correct results in every case.
您的定期约会开始日期是闰月日期。在非闰年中，定期约会的这个事件将会发生在前一个月。

One code-writer's trick, for instance, was to encode dates using the 1, 461 days that make up a full leap-year cycle.
ECONOMIST: Financial technology: Beware the millennium The
The 23-year-old honey from Holland made a long-legged leap up the charts from her second-to-last position last year.
FORBES: Magazine Article

A leap year is a year which has 366 days. The extra day is February 29th. There is a leap year every four years.