嗨Levimatt，

请注意，ECMA-376中的日期存储为数字值（序列日期）。

Hi Levimatt,

Please be aware that dates in ECMA-376 are stored as numeric values (serial dates).

DateTime oaDate = new DateTime(2009, 12, 11);
double oaValue = oaDate.ToOADate();
Console.WriteLine("Serial value of date 2009-12-11: " + oaValue);
            
DateTime newDate = DateTime.FromOADate(oaValue);
Console.WriteLine("DateTime of serial date value (40158): " + oaDate);

Console.Read();

以上结果在控制台中显示：

The above results in this in the console:

Serial value of date 2009-12-11: 40158
DateTime of serial date value (40158): 11-12-2009 00:00:00

在.Net-terms 您所体验的东西被称为"OADate"（OLE自动化日期）

我希望这会有所帮助，

：o）

In .Net-terms what you experience is called an "OADate" (OLE Automation Date)

I hope this helps,

:o)