Thanks for your posting and using Aspose.Cells for Java.
It is working fine. Please try the latest version: Aspose.Cells for Java 16.11.0 with the following sample code. I have also shown its console output for your reference.
Java
Workbook workbook = new Workbook(dirPath + “DateValues.xlsx”);
Worksheet ws = workbook.getWorksheets().get(0);
Cell cell = ws.getCells().get(“E3”);
if(cell.getType() == CellValueType.IS_DATE_TIME)
{
System.out.println("Its date value: " + cell.getStringValue());