获取当月的月初和月末

刚碰见个这样的需求,忽然之间发现不会写,度娘以后记录下来分享一下

function getLastDay(){
    var now = new Date();
    var year = now.getFullYear();
    var month = now.getMonth() + 1;
    if(month>12){
        month -=12;
        year++;
    }
    var new_date = new Date(year,month,1);
    var pre_month = "";
    if(month < 10){
        pre_month = "0";
    }
    var first = "" + year + "-" + pre_month + month + "-01" + " 00:00:00";
    var end = "" + year + "-" + pre_month + month + "-" + (new Date(new_date.getTime()-1000*60*60*24)).getDate() + " 23:59:59";
    console.log(first)
    console.log(end)
    console.log(new Date(new_date.getTime()))
    console.log(new Date(new_date.getTime()-1000*60*60*24) + "23:59:59")
}