Javascript Date常用示例

一.比较时间的大小（由页面插件选择的日期时间）

    var startDateStr = '2017-03-11 10:00:00';
    var endDateStr = '2017-03-11 9:59:59';
    var startDate = dateFormat(startDateStr);
    var endDate = dateFormat(endDateStr);
    if ((startDate-endDate) >= 0) {
        alert('结束时间必须大于开始时间');
    }
    function dateFormat(dateStr) {
        if (dateStr.indexOf(':') > -1){     //日期+时间
            var tempArr = dateStr.split(' ');
            var dArr =  tempArr[0].replace(/[-\/]/g, ',').split(',');
            var tArr =  tempArr[1].replace(/(:)/g, ',').split(',');
            return new Date(parseInt(dArr[0]), parseInt(dArr[1]), parseInt(dArr[2]), parseInt(tArr[0]), parseInt(tArr[1]), parseInt(tArr[2]));
        } else {                          //日期
            var dArr =  dateStr.replace(/[-\/]/g, ',').split(',');
            return new Date(parseInt(dArr[0]), parseInt(dArr[1]), parseInt(dArr[2]));
        }
    }

二.将后台取出的时间戳转化成指定格式的日期

function getDate(date, format) {
    // format: yyyy-MM-dd hh:mm:ss
    if (/(y+)/.test(format)) {
        format = format.replace(RegExp.$1, (date.getFullYear() + '').substring(4 - RegExp.$1.length));
    }
    var o = {
        '(M+)': date.getMonth(),
        '(d+)': date.getDate(),
        '(h+)': date.getHours(),
        '(m+)': date.getMinutes(),
        '(s+)': date.getSeconds()
    };
    for (var key in o) {
        var reg = new RegExp(key);
        if (reg.test(format)) {
            format = format.replace(RegExp.$1, addLeftZero(o[key] + ''));
        }
    }
    return format;
};

function addLeftZero(str) {
    return str.length > 1 ? str : '0' + str;
}

三.求时间差（天、时、分、秒）

var startDateStr = '2017-03-11 10:00:00';       //假定获取的input中时间值
var endDateStr = '2017-03-12 10:59:59';
remainTime(startDateStr,endDateStr);
function remainTime(startDateStr, endDateStr) {
    var startDate = dateFormat(startDateStr);
    var endDate = dateFormat(endDateStr);
    var t = (endDate - startDate)/1000;      //相差秒数   等价于=>(endDate.getTime() - startDate.getTime())/1000
    var days = Math.floor(t/86400);            //相差天数
    var hours = Math.floor(t%86400/3600);      //相差小时
    var minutes = Math.floor(t%86400%3600/60); //相差分钟
    var seconds = Math.floor(t%60);            //相差秒
    console.log(days+'天'+hours+'小时'+minutes+'分钟'+seconds+'秒');  //1天0小时59分钟59秒
}
//转化为时间对象Object
function dateFormat(dateStr) {
    if (dateStr.indexOf(':') > -1){     //日期+时间
        var tempArr = dateStr.split(' ');
        var dArr =  tempArr[0].replace(/[-\/]/g, ',').split(',');
        var tArr =  tempArr[1].replace(/(:)/g, ',').split(',');
        return new Date(parseInt(dArr[0]), parseInt(dArr[1]), parseInt(dArr[2]), parseInt(tArr[0]), parseInt(tArr[1]), parseInt(tArr[2]));
    } else {                          //日期
        var dArr =  dateStr.replace(/[-\/]/g, ',').split(',');
        return new Date(parseInt(dArr[0]), parseInt(dArr[1]), parseInt(dArr[2]));
    }
}