function getVirtulData(year) {
    year = year || '2020';
    var date = +echarts.number.parseDate(year + '-01-01');
    var end = +echarts.number.parseDate((+year + 1) + '-01-01');
    var dayTime = 3600 * 24 * 1000;
    var data = [];
    for (var time = date; time < end; time += dayTime) {
        data.push([
            echarts.format.formatTime('yyyy-MM-dd', time),
            Math.floor(Math.random() * 1000)
        ]);
    }
    return data;
}

//调用
getVirtulData(2019);

Done!