js 格式化时间

        Date.prototype.format = function(format){             
             var o = {
              "M+" :  this.getMonth()+1,  //month
              "d+" :  this.getDate(),     //day
              "h+" :  this.getHours(),    //hour
                  "m+" :  this.getMinutes(),  //minute
                  "s+" :  this.getSeconds(), //second
                  "q+" :  Math.floor((this.getMonth()+3)/3),  //quarter
                  "S"  :  this.getMilliseconds() //millisecond
               }
             
               if(/(y+)/.test(format)) {
                format = format.replace(RegExp.$1, (this.getFullYear()+"").substr(4 - RegExp.$1.length));
               }
             
               for(var k in o) {
                if(new RegExp("("+ k +")").test(format)) {
                  format = format.replace(RegExp.$1, RegExp.$1.length==1 ? o[k] : ("00"+ o[k]).substr((""+ o[k]).length));
                }
               }
             return format;
        }

                var now = new Date();
                var nowStr = now.format("yyyy-MM-dd hh:mm:ss");