xaxis的type为time时echarts4的柱状图只能从原点开始

描述:当前是关于Echarts图表中的 柱状图 示例。
 
            option = {
    title: {
        text: '项目实施进度表',
        left: 10
    },
    legend: {
        y: 'bottom',
        data: ['计划时间', '实际时间'] //修改的地方1

    },
    grid: {
        containLabel: true,
        left: 20
    },
    xAxis: {
        type: 'time'
    },

    yAxis: {

        data: ['任务一', '任务二', '任务三', '任务四', '任务五', '任务六', '任务七']

    },
    tooltip: {
        trigger: 'axis',
        formatter: function(params) {
            var res = params[0].name + "</br>"
            var date0 = params[0].data;
            return date0;
        }
    },
    series: [

        {
            name: '计划开始时间',
            type: 'bar',
            stack: 'test1',
            itemStyle: {
                normal: {
                    color: 'rgba(0,0,0,0)'
                }
            },
            data: [
                new Date('2019/3/9'),
                new Date('2019/3/10'),
                new Date('2019/3/11'),
                new Date('2019/3/12'),
                new Date('2019/3/13'),
                new Date('2019/3/14'),
                new Date('2019/3/15')
            ]
        },
        {
            name: '计划时间',
            type: 'bar',
            stack: 'test1',
            //修改地方2
            itemStyle: {
                normal: {
                    color: '#F98563'
                }
            },
            data: [
                new Date('2019/3/12'),
                new Date('2019/3/13'),
                new Date('2019/3/14'),
                new Date('2019/3/15'),
                new Date('2019/3/16'),
                new Date('2019/3/17'),
                new Date('2019/3/18')
            ]
        },
        {
            name: '实际开始时间',
            type: 'bar',
            stack: 'test2',
            itemStyle: {
                normal: {
                    color: 'rgba(0,0,0,0)'
                }
            },
            data: [
                new Date('2019/3/12'),
                new Date('2019/3/13'),
                new Date('2019/3/14'),
                new Date('2019/3/15'),
                new Date('2019/3/16'),
                new Date('2019/3/17'),
                new Date('2019/3/18')
            ]
        },
        {
            name: '实际时间',
            type: 'bar',
            stack: 'test2',
            //修改地方3
            itemStyle: {
                normal: {
                    color: '#A2E068'
                }
            },
            data: [
                new Date('2019/3/22'),
                new Date('2019/3/23'),
                new Date('2019/3/24'),
                new Date('2019/3/25'),
                new Date('2019/3/26'),
                new Date('2019/3/27'),
                new Date('2019/3/28')
            ]
        }
    ]
};