说明：  气象资料处理中经常会涉及到年日数和月日数的计算，在这里分享两个VB编程中经常会用到的函数：年日数和月日数计算
(Meteorological data processing often involves the calculation of the annual number of days and months days, share the two VB programming is often used in the function here: the annual number of days and months the number of days)