cell.setCellValue(new Date());
// we style the second cell as a date (and time). It is important to
// create a new cell style from the workbook otherwise you can end up
// modifying the built in style and effecting not only this cell but other cells.
CellStyle cellStyle = wb.createCellStyle();
cellStyle.setDataFormat(createHelper.createDataFormat().getFormat("m/d/yy h:mm"));
cell = row.createCell((short)1);
cell.setCellValue(new Date());
cell.setCellStyle(cellStyle);
// Write the output to a file