主题：指定时间内自动打开窗口

 参考

Dim str As String = Format(Date.Today, "MMdd")
If str >= "0501" AndAlso str <= "0930" Then
    forms("春季").show
    forms("冬季").close
ElseIf str >= "1001" OrElse str <= "0430" Then
    forms("冬季").show
    forms("春季").Close
End If