var data1 = [
    {
        name: "Doctor 1", 
        value: [
            {start: "December 17, 2012 21:00:00", end: "December 17, 2012 23:00:00"}, 
            {start: "December 17, 2012 23:30:00", end: "December 18, 2012 11:00:00"}
        ]
    }, {
        name: "Doctor 2", 
        value: {start: "December 17, 2012 23:00:00", end: "December 17, 2012 23:30:00"}
    }, {
        name: "Doctor 3", 
        value: {start: "December 17, 2012 23:30:00", end: "December 18, 2012 00:05:00"}
    }
];

var options1 = {
    id: "demo1", 
    width: 1100, 
    height: 250,
    data: {
        plain: data1,
    },
    labelMargin: -20 // change margin of label
    title: {
        text: "Change Label Margin"
    },
    axis: {
        x: {
            label: {
                text: ""
            }
        }
    },
};
var timeline = new C9.TimeLine(options1);
timeline.draw();