var time = {
    'second': 1000,
    'minute': 1000 * 60,
    'hour'  : 1000 * 60 * 60,
    'day'   : 1000 * 60 * 60 * 24,
    'week'  : 1000 * 60 * 60 * 24 * 7
};

var time = {
    'second': 1000,
    'minute': this.second * 60,
    'hour'  : this.minute * 60,
    'day'   : this.hour   * 24,
    'week'  : this.day    * 7
}

var time = {};
time.second = 1000;
time.minute = time.second * 60;
...

var time = (function(){
    var second = 1000,
        minute = second * 60,
        hour = minute * 60,
        day = hour * 24,
        week = day * 7;
    return {
        'second': second,
        'minute': minute,
        'hour'  : hour,
        'day'   : day,
        'week'  : week
    };
})();

var time = (function(){
    var w, d, h, m, s;
    w = (d = (h = (m = (s = 1000) * 60) * 60) * 24) * 7;
    return {
        second: s,
        minute: m,
        hour  : h,
        day   : d,
        week  : w
    };
})();

var time=function(){var a,b,c,d,e;a=(b=(c=(d=(e=1e3)*60)*60)*24)*7;return{second:e,minute:d,hour:c,day:b,week:a}}()

function Time() {
    this.second = 1000;
    this.minute = this.second * 60;
    this.hour = this.minute * 60;
    this.day = this.hour * 24;
    this.week = this.day * 7;
}

// Use
var time = new Time();

var time = {
    'second': 1000,
     get minute () {
       return this.second * 60;
     },
     get hour (){
       return this.minute * 60;
     },
     get day (){
       return this.hour * 24;
     },
     get week (){
       return this.day * 7;
     }
};