C# Julian 日期解析器
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/513247/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
C# Julian Date Parser
提问by Jake Pearson
I have a cell in a spreadsheet that is a date object in Excel but becomes a double (something like 39820.0 for 1/7/2009) when it comes out of C1's xls class. I read this is a Julian date format. Can someone tell me how to parse it back into a DateTime in C#?
我在电子表格中有一个单元格，它是 Excel 中的日期对象，但是当它从 C1 的 xls 类中出来时变成了双精度（类似于 2009 年 1 月 7 日的 39820.0）。我读到这是儒略日期格式。有人能告诉我如何将它解析回 C# 中的 DateTime 吗？
Update: It looks like I might not have a Julian date, but instead the number of days since Dec 30, 1899.
更新：看起来我可能没有 Julian 日期，而是自 1899 年 12 月 30 日以来的天数。
采纳答案by GBegen
I think Excel is just using the standard OLE Automation DATEtype which can be converted with the DateTime.FromOADatemethod.
我认为 Excel 只是使用标准的 OLE 自动化DATE类型，可以使用该DateTime.FromOADate方法进行转换。
This block of code,
这段代码，
using System;
namespace DateFromDouble
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine(DateTime.FromOADate(39820.0));
}
}
}
outputs:
输出：
1/7/2009 12:00:00 AM
回答by Kevin Babcock
回答by Kieron
That number looks like a 'number of days since 1900' value.
该数字看起来像是“自 1900 年以来的天数”值。
回答by BFree
There's a JulianCalendar class in System.Globalization; Here's how you would use it:
System.Globalization 中有一个 JulianCalendar 类；以下是您将如何使用它：
JulianCalendar c = new JulianCalendar();
DateTime time = c.ToDateTime(2009, 1, 7, 0, 0, 0, 0);
Console.WriteLine(time.ToShortDateString());
EDIT:
编辑：
If it is in fact days since "1900" here's how you can do it:
如果实际上是自“1900”以来的几天，那么您可以这样做：
public static DateTime DaysSince1900(int days)
{
return new DateTime(1900, 1, 1).AddDays(days);
}
DateTime time = DaysSince1900(39820);
Console.WriteLine(time.ToShortDateString()); //will result in "1/9/2009"
回答by localman
回答by Metro Smurf
When dealing with Excel dates, the date may be the string representation of a date, or it may be an OA date. This is an extension method I wrote a while back to help facilitate the date conversion:
在处理 Excel 日期时，日期可能是日期的字符串表示，也可能是 OA 日期。这是我不久前写的一个扩展方法，以帮助促进日期转换：
/// <summary>
/// Sometimes the date from Excel is a string, other times it is an OA Date:
/// Excel stores date values as a Double representing the number of days from January 1, 1900.
/// Need to use the FromOADate method which takes a Double and converts to a Date.
/// OA = OLE Automation compatible.
/// </summary>
/// <param name="date">a string to parse into a date</param>
/// <returns>a DateTime value; if the string could not be parsed, returns DateTime.MinValue</returns>
public static DateTime ParseExcelDate( this string date )
{
DateTime dt;
if( DateTime.TryParse( date, out dt ) )
{
return dt;
}
double oaDate;
if( double.TryParse( date, out oaDate ) )
{
return DateTime.FromOADate( oaDate );
}
return DateTime.MinValue;
}
回答by Madcat
Just format the cell(s) in question as Date, use CTRL+1, and select the your desired format.
只需将有问题的单元格格式化为日期，使用 CTRL+1，然后选择所需的格式。
