Example:

Workbook book = new Workbook();
Worksheet sheet = book.getWorksheets().get(0);
Cells cells = sheet.getCells();
cells.get(0, 0).setValue("fruit");
cells.get(1, 0).setValue("grape");
cells.get(2, 0).setValue("blueberry");
cells.get(3, 0).setValue("kiwi");
cells.get(4, 0).setValue("cherry");

//Create date style
Style dateStyle = new CellsFactory().createStyle();
dateStyle.setCustom("m/d/yyyy");
cells.get(0, 1).setValue("date");
cells.get(1, 1).setValue(new DateTime(2021, 2, 5));
cells.get(2, 1).setValue(new DateTime(2022, 3, 8));
cells.get(3, 1).setValue(new DateTime(2023, 4, 10));
cells.get(4, 1).setValue(new DateTime(2024, 5, 16));
//Set date style
cells.get(1, 1).setStyle(dateStyle);
cells.get(2, 1).setStyle(dateStyle);
cells.get(3, 1).setStyle(dateStyle);
cells.get(4, 1).setStyle(dateStyle);

cells.get(0, 2).setValue("amount");
cells.get(1, 2).setValue(50);
cells.get(2, 2).setValue(60);
cells.get(3, 2).setValue(70);
cells.get(4, 2).setValue(80);

PivotTableCollection pivots = sheet.getPivotTables();
//Add a PivotTable
int pivotIndex = pivots.add("=Sheet1!A1:C5", "A12", "TestPivotTable");
PivotTable pivot = pivots.get(pivotIndex);
pivot.addFieldToArea(PivotFieldType.ROW, "fruit");
pivot.addFieldToArea(PivotFieldType.COLUMN, "date");
pivot.addFieldToArea(PivotFieldType.DATA, "amount");
pivot.setPivotTableStyleType(PivotTableStyleType.PIVOT_TABLE_STYLE_MEDIUM_10);

//Refresh PivotTable data
pivot.refreshData();
pivot.calculateData();

//Add a new Timeline using PivotTable as data source
sheet.getTimelines().add(pivot, 10, 5, "date");

//Get Timeline object
Timeline timelineObj = sheet.getTimelines().get(0);



book.save("out.xlsx");

//do your business