ExcelSerialDate Class

Definition

Namespace

Bodu.Formats.Excel

Assembly

Bodu.Formats.Excel.Binary.dll

Package

Bodu.Formats.Excel.Binary 1.0.0

Source

ExcelSerialDate.cs

Converts Excel serial date numbers into calendar dates.

public static class ExcelSerialDate

Inheritance

object

ExcelSerialDate

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

Excel stores dates as floating-point serial numbers measured from the epoch 1899-12-30, deliberately preserving the historical 1900 leap-year bug so that values round-trip with Excel. The reader never infers that a numeric cell is a date; this helper is provided so a caller that knows a column holds dates can convert its values.

Methods

FromSerialDate(double)

Converts an Excel serial date number in the 1900 date system to a DateOnly, discarding any fractional time-of-day component.

public static DateOnly FromSerialDate(double serial)

Parameters

serial double

The Excel serial date number.

Returns

DateOnly

The calendar date represented by serial.

Exceptions

ArgumentException

Thrown when serial is outside the range of representable OLE Automation dates.

FromSerialDate(double, ExcelDateSystem)

Converts an Excel serial date number to a DateOnly using the specified date system, discarding any fractional time-of-day component.

public static DateOnly FromSerialDate(double serial, ExcelDateSystem dateSystem)

Parameters

serial double

The Excel serial date number.

dateSystem ExcelDateSystem

The date system that establishes the serial number's epoch.

Returns

DateOnly

The calendar date represented by serial.

Exceptions

ArgumentException

Thrown when serial is outside the range of representable OLE Automation dates.

ToDateTime(double)

Converts an Excel serial date number in the 1900 date system to a DateTime, preserving any fractional time-of-day component.

public static DateTime ToDateTime(double serial)

Parameters

serial double

The Excel serial date number.

Returns

DateTime

The date and time represented by serial.

Examples

using Bodu.Formats.Excel;

// Serial 25569 is 1970-01-01 in the default 1900 date system.
DateTime epoch = ExcelSerialDate.ToDateTime(25569);

Exceptions

ArgumentException

Thrown when serial is outside the range of representable OLE Automation dates.

ToDateTime(double, ExcelDateSystem)

Converts an Excel serial date number to a DateTime using the specified date system, preserving any fractional time-of-day component.

public static DateTime ToDateTime(double serial, ExcelDateSystem dateSystem)

Parameters

serial double

The Excel serial date number.

dateSystem ExcelDateSystem

The date system that establishes the serial number's epoch.

Returns

DateTime

The date and time represented by serial.

Examples

using Bodu.Formats.Excel;

// Convert a date-formatted numeric cell using the workbook's own date system.
using var workbook = ExcelBinaryWorkbook.OpenRead("report.xls");
using ExcelWorksheetReader reader = workbook.OpenWorksheet(0);
while (reader.TryReadCell(out ExcelCell cell))
{
    if (cell.IsDateFormatted && cell.NumberValue is double serial)
        Console.WriteLine(ExcelSerialDate.ToDateTime(serial, workbook.DateSystem));
}

Exceptions

ArgumentException

Thrown when serial is outside the range of representable OLE Automation dates.

Applies to

Product	Versions
.NET	8, 10