Excel宏运行时触发Run-time Error '6'溢出错误求助

我正在编写一个Excel宏，功能是基于三个日期中的最早日期执行操作，目前仅完成基础框架，用MsgBox做测试。宏代码如下：

Sub HighlightNextEDM()

Dim LastDate1 As Date
Dim LastDate2 As Date
Dim LastDate3 As Date
Dim OldestDate As Date

LastDate1 = Sheet1.Range("F11")
LastDate2 = Sheet1.Range("F12")
LastDate3 = Sheet1.Range("F13")
OldestDate = Application.WorksheetFunction.Min(LastDate1, LastDate2, LastDate3)

MsgBox "LastDate1 = " & LastDate1 & vbNewLine & _
        "LastDate2 = " & LastDate2 & vbNewLine & _
        "LastDate3 = " & LastDate3 & vbNewLine & _
        "OldestDate= " & OldestDate

If OldestDate = LastDate1 Then
    MsgBox "LastDate1 is the oldest!"
ElseIf OldestDate = LastDate2 Then
    MsgBox "LastDate2 is the oldest!"
ElseIf OldestDate = LastDate3 Then
    MsgBox "LastDate3 is the oldest!"
End If

End Sub

单元格F11的值为1/1/2025 12:25:00 PM，F12的值为12/15/2024 8:35:00 AM，F13的值为3/1/2025 9:02:00 AM。

运行宏时，第一个显示所有日期的MsgBox可正常工作，但执行到If OldestDate = LastDate1 Then行时，触发Run-time Error '6'溢出错误。我尝试过将数据类型改为Double、赋值时使用*.Value*、将值转换为字符串等方法，均未解决问题，恳请各位提供帮助！

内容的提问来源于stack exchange，提问作者Chi-town Brad