DateTime is rounded up to the next day using ExcelLibrary - excel

Question

The datetime I'm writing to Excel always get rounded up to the next day:
workSheet.Cells[0, 0] = new Cell(DateTime.Now, new CellFormat(CellFormatType.DateTime, #"HH:mm:ss"));
In the output Excel file the cell gets this value: 29/09/2013 00:00:00
The DateTime.Now from this example is 28/09/2013 19:42:23

Answer 1

I ended up passing the cell value as a string instead of as a DateTime:
workSheet.Cells[0, 0] = new Cell(DateTime.Now.ToString(#"HH:mm:ss:ff"),
new CellFormat(CellFormatType.DateTime, #"HH:mm:ss"));

Answer 2

If you are using the ExcelLibrary Project Source Code, you can fix this by:
Go to SharedResource Class in this location: [Project Source Code folder]\Office\BinaryFileFormat folder
Change the EncodeDateTime function as below:
public double EncodeDateTime(DateTime value)
{
double days = (value - BaseDate).Days;
//if (days > 365) days++;
return days;
}
Pass the DataTime object to the Cell with the prefered format:
worksheet.Cells[iIndex, j] = new Cell(((DateTime)cellValue), new CellFormat(CellFormatType.DateTime, #"dd/MM/yyyy"));

Answer 3

You need to convert the date format from OLE Automation to the .net format by using DateTime.FromOADate.
If oCell.Format.FormatType = CellFormatType.Date OrElse oCell.Format.FormatType = CellFormatType.DateTime Then
Dim d As Double = Double.Parse(oCell.Value)
Debug.print(DateTime.FromOADate(d))
End If