// Create a new workbook Workbook workbook = new Workbook(); IWorksheet worksheet = workbook.getWorksheets().get(0); worksheet.getRange("A:F").setColumnWidth(17); worksheet.getRange("A1:F1").setFormula("= Now()"); // Apply different date formats. worksheet.getRange("A1").setNumberFormat("m/d/yy"); worksheet.getRange("B1").setNumberFormat("d-mmm-yy"); worksheet.getRange("C1").setNumberFormat("dddd"); // Apply different time formats. worksheet.getRange("D1").setNumberFormat("m/d/yy h:mm"); worksheet.getRange("E1").setNumberFormat("h:mm AM/PM"); worksheet.getRange("F1").setNumberFormat("h:mm:ss"); // Save to an excel file workbook.save("DateAndTimeFormat.xlsx");