bar8.vl

{
    "mark": "bar",
    "data": {
        "values": [
            {
                "start": 1,
                "end": 3,
                "task": "A"
            },
            {
                "start": 3,
                "end": 8,
                "task": "B"
            },
            {
                "start": 8,
                "end": 10,
                "task": "C"
            }
        ]
    },
    "$schema": "https://vega.github.io/schema/vega-lite/v3.json",
    "encoding": {
        "x2": {
            "field": "end"
        },
        "x": {
            "field": "start",
            "type": "quantitative"
        },
        "y": {
            "field": "task",
            "type": "ordinal"
        }
    },
    "description": "A simple bar chart with ranged data (aka Gantt Chart)."
}