# Event Versions (JavaScript Scheduler) | DayPilot Pro for JavaScript Demo

> Read more about the [event versions](https://doc.daypilot.org/scheduler/event-versions/).

## Links

- Canonical HTML: /demo/scheduler/eventversions.html
- Source HTML folder: /demo/scheduler/
- Catalog root: /demo/
- Catalog: /demo/llms.txt

## Source

### Inline demo script 1

```javascript
const dp = new DayPilot.Scheduler("dp", {
            eventVersionsEnabled: true,
            eventVersionHeight: 15,
            eventVersionsReserveSpace: true,
            startDate: "2026-01-01",
            days: 365,
            scale: "Day",
            timeHeaders: [
                {groupBy: "Month", format: "MMM yyyy"},
                {groupBy: "Cell", format: "d"}
            ],
            treeEnabled: true,
            resources: [
                {
                    name: "Locations", id: "G1", expanded: true, children: [
                        {name: "Room 1", id: "A"},
                        {name: "Room 2", id: "B"},
                        {name: "Room 3", id: "C"},
                        {name: "Room 4", id: "D"}
                    ]
                },
                {
                    name: "People", id: "G2", expanded: true, children: [
                        {name: "Person 1", id: "E"},
                        {name: "Person 2", id: "F"},
                        {name: "Person 3", id: "G"},
                        {name: "Person 4", id: "H"}
                    ]
                },
                {
                    name: "Tools", id: "G3", expanded: true, children: [
                        {name: "Tool 1", id: "I"},
                        {name: "Tool 2", id: "J"},
                        {name: "Tool 3", id: "K"},
                        {name: "Tool 4", id: "L"}
                    ]
                },
            ],
            onTimeRangeSelected: async args => {
                const modal = await DayPilot.Modal.prompt("New event name:", "Event");
                dp.clearSelection();
                if (modal.canceled) {
                    return;
                }
                dp.events.add({
                    start: args.start,
                    end: args.end,
                    id: DayPilot.guid(),
                    resource: args.resource,
                    text: modal.result
                });
                dp.message("Created");
            },
            height: 300
        });
        dp.init();
        dp.scrollTo("2026-03-25");

        const app = {
            init() {
                this.addEventHandlers();
                this.loadEventData();
            },
            loadEventData() {
                const events = [];

                for (let i = 0; i < 12; i++) {
                    const duration = Math.floor(Math.random() * 6) + 1; // 1 to 6
                    const durationDays = Math.floor(Math.random() * 6); // 0 to 5
                    const start = Math.floor(Math.random() * 6) + 2; // 2 to 7

                    const e = {
                        start: new DayPilot.Date("2026-03-25T00:00:00").addDays(start),
                        end: new DayPilot.Date("2026-03-25T12:00:00").addDays(start).addDays(durationDays).addHours(duration),
                        id: DayPilot.guid(),
                        resource: String.fromCharCode(65 + i),
                        text: `Event ${i + 1}`,
                        versions: [
                            {
                                start: new DayPilot.Date("2026-03-25T00:00:00").addDays(start),
                                end: new DayPilot.Date("2026-03-25T12:00:00").addDays(start).addDays(durationDays).addHours(duration).addDays(1),
                                barHidden: true,
                            }
                        ]
                    };
                    events.push(e);
                }
                dp.update({events});
            },
            addEventHandlers() {
                document.querySelector("#position").addEventListener("change", function() {
                    dp.eventVersionPosition = this.value;
                    dp.update();
                });
            }
        };
        app.init();
```