js日期相减

// var date = "2019-06-24 11:55:00",date2 = "2019-06-24 14:05:00";

function dateLess(fromDate, toDate){
        var date = new Date(fromDate);
        var date2 = new Date(toDate);
        var s1 = date.getTime(),s2 = date2.getTime();
        var total = (s2 - s1)/1000;
        var day = parseInt(total / (24*60*60));//计算整数天数
        var afterDay = total - day*24*60*60;//取得算出天数后剩余的秒数
        var hour = parseInt(afterDay/(60*60));//计算整数小时数
        var afterHour = total - day*24*60*60 - hour*60*60;//取得算出小时数后剩余的秒数
        var min = parseInt(afterHour/60);//计算整数分
        var afterMin = total - day*24*60*60 - hour*60*60 - min*60;//取得算出分后剩余的秒数

        if(day === 0){
            if(hour === 0){
                return min+"分"+afterMin+"秒";
            }else{
                return hour+"时"+min+"分"+afterMin+"秒";
            }
        }else{
            return day+"天"+hour+"时"+min+"分"+afterMin+"秒";
        }
    }