Calendar heatmap horizontal: error when computers sets with timezone UTC < -3

[brunolajoie]

One-line summary [问题简述]

Echarts calendar heat map does not work on client's browsers when their computers are set to a timezone of UTC -3 or below (for instance, in the US). Error: "Uncaught TypeError: Cannot read property '0' of undefined"

Version & Environment [版本及环境]

• ECharts version [ECharts 版本]: 3 (https://ecomfe.github.io/echarts-examples/public/#chart-type-calendar)
• Browser version [浏览器类型和版本]: Chrome 60.0.3112.101
• OS Version [操作系统类型和版本]: MacOSX 10.12.6

Expected behaviour [期望结果]

Normal display of the chart

ECharts option [ECharts配置项]

option = {
tooltip: {
        position: 'top'
    },
    visualMap: {
        min: 0,
        max: 1000,
        calculable: true,
        orient: 'horizontal',
        left: 'center',
        top: 'top'
    },

    calendar: [
    {
        range: '2017',
        cellSize: ['auto', 20]
    },
    {
        top: 260,
        range: '2016',
        cellSize: ['auto', 20]
    },
    {
        top: 450,
        range: '2015',
        cellSize: ['auto', 20],
        right: 5
    }],

    series: [{
        type: 'heatmap',
        coordinateSystem: 'calendar',
        calendarIndex: 0,
        data: getVirtulData(2017)
    }, {
        type: 'heatmap',
        coordinateSystem: 'calendar',
        calendarIndex: 1,
        data: getVirtulData(2016)
    }, {
        type: 'heatmap',
        coordinateSystem: 'calendar',
        calendarIndex: 2,
        data: getVirtulData(2015)
    }]
}

Other comments [其他信息]

The error can easily be reproduced at the demo page https://ecomfe.github.io/echarts-examples/public/editor.html?c=calendar-horizontal as long as timezone setting is set to UTC -3 or below. Error disappear when changing the timezone to European or Asian ones

NORMAL BEHAVIOR

BUGGING BEHAVIOR:

[100pah]

I am being puzzled with this issue:

When I set system timezone as "Time Zone: America/Toronto",
those code will get different result:

new Date(1478411999999).getTimezoneOffset();  // get 240
new Date(1478412000000).getTimezoneOffset();  // get 300

Do you know any hint about this issue?

[brunolajoie]

@100pah I think this may help fix the bug https://stackoverflow.com/questions/2771609/how-to-ignore-users-time-zone-and-force-date-use-specific-time-zone