var date =newDate();var year = date.getFullYear();var month = date.getMonth()+1;var lastDay=nextMonthDay(year, month);//该月最后一天日期var xqj =newDate().getDay();//判断星期几,0为星期天,1-6 为星期一至六
计算每月天数
functionnextMonthDay(year, month){//判断每月多少天 var day31 =[1,3,5,7,8,10,12];var day30 =[4,6,9,11];if(day31.indexOf(month)>-1){return31;}elseif(day30.indexOf(month)>-1){return30;}else{if(isLeapYear(year)){return29;}else{return28;}}}
判断是否为闰年
functionisLeapYear(year){//判断是否为闰年return(year %4==0)&&(year %100!=0|| year %400==0);}