//指定日期一月的天数 function maxDay() { //字符串日期格式"2020-12-12" var sDate = $('#startDate').val(); //转换为日期 var startDate = new Date(sDate) var endDate = startDate.setMonth(startDate.getMonth()+1); endDate = formatDate(endDate); var days = daysBetween(sDate,endDate); return days; } //指定日期获取一个月 function formatDate(date) { var date = new Date(date); var YY = date.getFullYear() + '-'; var MM = (date.getMonth() + 1 < 10 ? '0' + (date.getMonth() + 1) : date.getMonth() + 1) + '-'; var DD = (date.getDate() < 10 ? '0' + (date.getDate()) : date.getDate()); return YY + MM + DD; } //计算两日期天数 function daysBetween(sDate1,sDate2){ var time1 = Date.parse(new Date(sDate1)); var time2 = Date.parse(new Date(sDate2)); var nDays = Math.abs(parseInt((time2 - time1)/1000/3600/24)); return nDays; };