轻松实现公历年月日与简化儒略日的相互转换、公历年月日与年积日德相互转换，只需输入数据就行了-Easy to Gregorian calendar date and simplify the mutual conversion of the Julian day, calendar date and annual German conversion, simply enter the data on the line

由年积日和月，天的转换.首先要判断闰年，1900,2100要注意不是闰年-convert of day of year,between month/day of month