js 时间戳转时间工具类 js时间戳与时间互转

/**
 * 时间戳格式化函数
 * @param  {string} format    格式
 * @param  {int}    timestamp 要格式化的时间 默认为当前时间
 * @return {string}           格式化的时间字符串
 */
function date(format, timestamp){
    var a, jsdate=((timestamp) ? new Date(timestamp*1000) : new Date());
    var pad = function(n, c){
        if((n = n + "").length < c){
            return new Array(++c - n.length).join("0") + n;
        } else {
            return n;
        }
    };
    var txt_weekdays = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
    var txt_ordin = {1:"st", 2:"nd", 3:"rd", 21:"st", 22:"nd", 23:"rd", 31:"st"};
    var txt_months = ["", "January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
    var f = {
        // Day
        d: function(){return pad(f.j(), 2)},
        D: function(){return f.l().substr(0,3)},
        j: function(){return jsdate.getDate()},
        l: function(){return txt_weekdays[f.w()]},
        N: function(){return f.w() + 1},
        S: function(){return txt_ordin[f.j()] ? txt_ordin[f.j()] : 'th'},
        w: function(){return jsdate.getDay()},
        z: function(){return (jsdate - new Date(jsdate.getFullYear() + "/1/1")) / 864e5 >> 0}, 

        // Week
        W: function(){
            var a = f.z(), b = 364 + f.L() - a;
            var nd2, nd = (new Date(jsdate.getFullYear() + "/1/1").getDay() || 7) - 1;
            if(b <= 2 && ((jsdate.getDay() || 7) - 1) <= 2 - b){
                return 1;
            } else{
                if(a <= 2 && nd >= 4 && a >= (6 - nd)){
                    nd2 = new Date(jsdate.getFullYear() - 1 + "/12/31");
                    return date("W", Math.round(nd2.getTime()/1000));
                } else{
                    return (1 + (nd <= 3 ? ((a + nd) / 7) : (a - (7 - nd)) / 7) >> 0);
                }
            }
        }, 

        // Month
        F: function(){return txt_months[f.n()]},
        m: function(){return pad(f.n(), 2)},
        M: function(){return f.F().substr(0,3)},
        n: function(){return jsdate.getMonth() + 1},
        t: function(){
            var n;
            if( (n = jsdate.getMonth() + 1) == 2 ){
                return 28 + f.L();
            } else{
                if( n & 1 && n < 8 || !(n & 1) && n > 7 ){
                    return 31;
                } else{
                    return 30;
                }
            }
        }, 

        // Year
        L: function(){var y = f.Y();return (!(y & 3) && (y % 1e2 || !(y % 4e2))) ? 1 : 0},
        //o not supported yet
        Y: function(){return jsdate.getFullYear()},
        y: function(){return (jsdate.getFullYear() + "").slice(2)}, 

        // Time
        a: function(){return jsdate.getHours() > 11 ? "pm" : "am"},
        A: function(){return f.a().toUpperCase()},
        B: function(){
            // peter paul koch:
            var off = (jsdate.getTimezoneOffset() + 60)*60;
            var theSeconds = (jsdate.getHours() * 3600) + (jsdate.getMinutes() * 60) + jsdate.getSeconds() + off;
            var beat = Math.floor(theSeconds/86.4);
            if (beat > 1000) beat -= 1000;
            if (beat < 0) beat += 1000;
            if ((String(beat)).length == 1) beat = "00"+beat;
            if ((String(beat)).length == 2) beat = "0"+beat;
            return beat;
        },
        g: function(){return jsdate.getHours() % 12 || 12},
        G: function(){return jsdate.getHours()},
        h: function(){return pad(f.g(), 2)},
        H: function(){return pad(jsdate.getHours(), 2)},
        i: function(){return pad(jsdate.getMinutes(), 2)},
        s: function(){return pad(jsdate.getSeconds(), 2)},
        //u not supported yet 

        // Timezone
        //e not supported yet
        //I not supported yet
        O: function(){
            var t = pad(Math.abs(jsdate.getTimezoneOffset()/60*100), 4);
            if (jsdate.getTimezoneOffset() > 0) t = "-" + t; else t = "+" + t;
            return t;
        },
        P: function(){var O = f.O();return (O.substr(0, 3) + ":" + O.substr(3, 2))},
        //T not supported yet
        //Z not supported yet 

        // Full Date/Time
        c: function(){return f.Y() + "-" + f.m() + "-" + f.d() + "T" + f.h() + ":" + f.i() + ":" + f.s() + f.P()},
        //r not supported yet
        U: function(){return Math.round(jsdate.getTime()/1000)}
    }; 

    return format.replace(/[\]?([a-zA-Z])/g, function(t, s){
        if( t!=s ){
            // escaped
            ret = s;
        } else if( f[s] ){
            // a date function exists
            ret = f[s]();
        } else{
            // nothing special
            ret = s;
        }
        return ret;
    });
}

调用方法 能够很方便的将时间戳转换成日期的格式，如：

date('Y-m-d','1350052653');//很方便的将时间戳转换成了2012-10-11
date('Y-m-d H:i:s','1350052653');//得到的结果是2012-10-12 22:37:33

================================================================================================================

// (2)、将指定日期转换为时间戳。
    var t = "2017-12-08 20:5:30";  // 月、日、时、分、秒如果不满两位数可不带0.
    var T = new Date(t);  // 将指定日期转换为标准日期格式。Fri Dec 08 2017 20:05:30 GMT+0800 (中国标准时间)
    console.log(T.getTime())  // 将转换后的标准日期转换为时间戳。