主题：去年同月最后一天,代码有问题

excel报表beforbuild事件: mydate是全局变量

Dim y As Integer = mydate.Year '指定年份
        Dim yd1 As New Date(y, 1, 1) '本年第一天
        Dim yd2 As New Date(y-1, 1, 1) '去年第一天
       
        Dim m As Integer = mydate.Month '指定月份
        Dim md1 As New Date(y, m, 1) '本月第一天
        Dim md2 As New Date(y, m, Date.DaysInMonth(y,m)) '本月最后一天
        Dim md3 As New Date(y-1, m, 1) '去年同月第一天
        Dim md4 As New Date(y-1, m, Date.DaysInMonth(y,m)) '去年同月最后一天

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唯独mydate 是2016年2月份时会报错，附图：

 

此主题相关图片如下：qq截图20160805155504.jpg

Dim d As Date = "2016-2-29"

msgbox(d.addYears(-1))

Dim d As Date = "2016-2-20"
d = d.AddMonths(1).addYears(-1)
d = new Date(d.Year, d.Month, 1)
d = d.AddDays(-1)
msgbox(d)

 好的，谢谢

帮助里的代码还是很扎实的，是我糊涂了，心不静，往往就会闹出自以为是的错误： 

 

Dim md4 As New Date(y-1, m, Date.DaysInMonth(y-1,m)) '去年同月最后一天