Several ways for JS to set the date format

//当前日期  yyyy-mm-dd
 function getNowFormatDate() {
     var date = new Date();
     var seperator1 = "-";
     var year = date.getFullYear();
     var month = date.getMonth() + 1;
     var strDate = date.getDate();
     if (month >= 1 && month <= 9) {
         month = "0" + month;
     }
     if (strDate >= 0 && strDate <= 9) {
         strDate = "0" + strDate;
     }
     var currentdate = year + seperator1 + month + seperator1 + strDate;
     return currentdate;
 }

 
 //传入一个日期,   要增加的天数, 返回对应日期, 例如传入new Date(), 1 得到的是明天;
//new Date(), -1 得到昨天 
function addDate(date,days){ 
     var d=new Date(date); 
     d.setDate(d.getDate()+days);
     var day = d.getDate()<=9 ? "0"+d.getDate():d.getDate();
     var m=d.getMonth()+1; 
     return d.getFullYear()+'-'+m+'-'+ day; 
} 


//相对于今天的日期,  传入1 得到明天, 传入-1得到昨天
function addDate(days){ 
    var d=new Date(); 
    d.setDate(d.getDate()+days); 
    var m=d.getMonth()+1; 
    if(m<=9){
    	m = "0"+m;
    }
    var day = d.getDate()<=9 ? "0"+d.getDate():d.getDate();
    return d.getFullYear()+'-'+m+'-'+day; 
}  

//传入时间,得到该时间的1号日期,该月份第一天 
function getCurrentMonthFirst(date){
   /* var date = new Date();*/
    date.setDate(1);
    var month = parseInt(date.getMonth()+1);
    var day = date.getDate();
    if (month < 10) {
        month = '0' + month
    }
    if (day < 10) {
        day = '0' + day
    }
    return date.getFullYear() + '-' + month + '-' + day;
}
 
//传入时间,得到该月份最后一天 
function getCurrentMonthLast(date){
   /* var date=new Date();*/
    var currentMonth=date.getMonth();
    var nextMonth=++currentMonth;
    var nextMonthFirstDay=new Date(date.getFullYear(),nextMonth,1);
    var oneDay=1000*60*60*24;
    var lastTime = new Date(nextMonthFirstDay-oneDay);
    var month = parseInt(lastTime.getMonth()+1);
    var day = lastTime.getDate();
    if (month < 10) {
        month = '0' + month
    }
    if (day < 10) {
        day = '0' + day
    }
/*    return new Date(date.getFullYear() + '-' + month + '-' + day );*/
    return  date.getFullYear() + '-' + month + '-' + day ;
}