Excel十进制格式到C#日期时间

DateTime.ParseExact( value.ToString(), "yyyymmdd" );

这个 ParseExact 方法允许您为转换的日期/时间指定格式字符串。在你的例子中:一个四位数的年,然后两位数的月,然后两位数的月日。

如果您想在应用程序范围内实现它,我会这样做。

System.Globalization.CultureInfo cultureInfo =
            new System.Globalization.CultureInfo("en-CA");
        // Defining various date and time formats.
        dateTimeInfo.LongDatePattern = "yyyyMMdd";
        dateTimeInfo.ShortDatePattern = "yyyyMMdd";
        dateTimeInfo.FullDateTimePattern = "yyyyMMdd";
        // Setting application wide date time format.
        cultureInfo.DateTimeFormat = dateTimeInfo;


    // Assigning our custom Culture to the application.
    //Application.CurrentCulture = cultureInfo;
    Thread.CurrentThread.CurrentCulture = cultureInfo;
    Thread.CurrentThread.CurrentUICulture = cultureInfo;

DateTime.Parse(excelDate);

一个不那么直观的答案。

var a = 20090701m;
var b = a / 10000;
var year = (int)b;
var c = (b - year) * 100;
var month = (int)c;
var day = (int)((c - month) * 100);
var dt = new DateTime(year, month, day);