如何将DateTime值转换为double？

Question

如何将DateTime值转换为double ？

Answer 1

If, by double you mean an OLE Automation date, then you can use DateTime.ToOADate() . From the linked MSDN topic:

An OLE Automation date is implemented as a floating-point number whose value is the number of days from midnight, 30 December 1899. For example, midnight, 31 December 1899 is represented by 1.0; 6 AM, 1 January 1900 is represented by 2.25; midnight, 29 December 1899 is represented by -1.0; and 6 AM, 29 December 1899 is represented by -1.25.

The base OLE Automation Date is midnight, 30 December 1899. The maximum OLE Automation Date is the same as MaxValue, the last moment of 31 December 9999.

If you're talking about some other date representation that can also be stored in a double , please specify...

Answer 2

DateTime.ToOADate（）转换为C＃中的双OLE自动化日期

Answer 3

Yes, OLE Automation date enable Datetime to convert to Decimal/double type. However, the outcome/value to decimal/double is not exact system Datetime .

For example,

Decimal dateIndDec = Convert.Decimal (Datetim.Today.ToOADate());

is not equal to MS SQL

 Select Convert (Decimal (10, 9), GetDate())

Conclusion: OLE Automation date is not a true system datetime info... cannot use it.

I've been searched everywhere about convert Datetime value to Decimal value in C# without any luck.

Answer 4

You can calculate difference between your DateTime and DateTime.MinValue, and then get any Total* value.

var difference = DateTime.Now - DateTime.MinValue;
Console.WriteLine(difference.TotalMinutes);
Console.WriteLine(difference.TotalMilliseconds);