JS如何按时间粒度获取date的时间差

获取date类型

var type = _xAxis[0].split(/-|:|\s/).length;

按时间粒度获取date的时间差

    function getDateDiffByType(newDate,endDate,type){
        newDate = new Date(newDate) == 'Invalid Date' ? newDate+':00' : newDate;
        endDate = new Date(endDate) == 'Invalid Date' ? endDate+':00' : endDate;
        var dateDiff = new Date(endDate)-new Date(newDate);
        var _date = new Date(dateDiff);
        var year = _date.getFullYear() - 1970;
        var month = _date.getMonth();
        switch (type) {
            case 1: {
                return year;
                break;
            }
            case 2: {
                return month+year*12;
                break;
            }
            case 3: {
                return dateDiff/1000/60/60/24;
                break;
            }
            case 4: {
                return dateDiff/1000/60/60;
                break;
            }
            case 5: {
                return dateDiff/1000/60;
                break;
            }
            case 6: {
                return dateDiff/1000;
                break;
            }
        }
    }　

附：date按时间粒度格式化

function dateFmtByType( _date,_type) {
		_date = new Date(_date) == 'Invalid Date' ? _date+':00' : _date;//"2017-02-12 12"是Invalid Date
		var date = new Date(_date);
		var fmt = ["yyyy","yyyy-MM","yyyy-MM-dd","yyyy-MM-dd hh","yyyy-MM-dd hh:mm","yyyy-MM-dd hh:mm:ss"];
		return date.dateFormat(fmt[_type-1]);
	}

附：date格式化代码("yyyy-MM-dd hh:mm:ss")

Date.prototype.dateFormat = function(fmt)   
{ //author: meizz   
  var o = {   
    "M+" : this.getMonth()+1,                 //月份   
    "d+" : this.getDate(),                    //日   
    "h+" : this.getHours(),                   //小时   
    "m+" : this.getMinutes(),                 //分   
    "s+" : this.getSeconds(),                 //秒   
    "q+" : Math.floor((this.getMonth()+3)/3), //季度   
    "S"  : this.getMilliseconds()             //毫秒   
  };   
  if(/(y+)/.test(fmt))   
    fmt=fmt.replace(RegExp.$1, (this.getFullYear()+"").substr(4 - RegExp.$1.length));   
  for(var k in o)   
    if(new RegExp("("+ k +")").test(fmt))   
  fmt = fmt.replace(RegExp.$1, (RegExp.$1.length==1) ? (o[k]) : (("00"+ o[k]).substr((""+ o[k]).length)));   
  return fmt;   
}