/**
* 获取本周、本季度、本月、上月的开始日期、结束日期
*/
var now = new Date(); //当前日期
var nowDayOfWeek = now.getDay(); //今天本周的第几天
var nowDay = now.getDate(); //当前日
var nowMonth = now.getMonth(); //当前月
var nowYear = now.getYear(); //当前年
nowYear += (nowYear < 2000) ? 1900 : 0; //
var lastMonthDate = new Date(); //上月日期
lastMonthDate.setDate(1);
lastMonthDate.setMonth(lastMonthDate.getMonth() - 1);
var lastYear = lastMonthDate.getYear();
var lastMonth = lastMonthDate.getMonth();
//格式化日期：yyyy-MM-dd
function formatDate(date) {
var myyear = date.getFullYear();
var mymonth = date.getMonth() + 1;
var myweekday = date.getDate();
if (mymonth < 10) {
mymonth = "0" + mymonth;
}
if (myweekday < 10) {
myweekday = "0" + myweekday;
}
return (myyear + "-" + mymonth + "-" + myweekday);
}
//获得某月的天数
function getMonthDays(myMonth) {
var monthStartDate = new Date(nowYear, myMonth, 1);
var monthEndDate = new Date(nowYear, myMonth + 1, 1);
var days = (monthEndDate - monthStartDate) / (1000 * 60 * 60 * 24);
return days;
}
//获得本季度的开始月份
function getQuarterStartMonth() {
var quarterStartMonth = 0;
if (nowMonth < 3) {
quarterStartMonth = 0;
}
if (2 < nowMonth && nowMonth < 6) {
quarterStartMonth = 3;
}
if (5 < nowMonth && nowMonth < 9) {
quarterStartMonth = 6;
}
if (nowMonth > 8) {
quarterStartMonth = 9;
}
return quarterStartMonth;
}
//获得本周的开始日期
function getWeekStartDate() {
var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek);
return formatDate(weekStartDate);
}
//获得本周的结束日期
function getWeekEndDate() {
var weekEndDate = new Date(nowYear, nowMonth, nowDay + (6 - nowDayOfWeek));
return formatDate(weekEndDate);
}
//获得上周的开始日期
function getLastWeekStartDate() {
var weekStartDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek - 7);
return formatDate(weekStartDate);
}
//获得上周的结束日期
function getLastWeekEndDate() {
var weekEndDate = new Date(nowYear, nowMonth, nowDay - nowDayOfWeek - 1);
return formatDate(weekEndDate);
}
//获得本月的开始日期
function getMonthStartDate() {
var monthStartDate = new Date(nowYear, nowMonth, 1);
return formatDate(monthStartDate);
}
//获得本月的结束日期
function getMonthEndDate() {
var monthEndDate = new Date(nowYear, nowMonth, getMonthDays(nowMonth));
return formatDate(monthEndDate);
}
//获得上月开始时间
function getLastMonthStartDate() {
var lastMonthStartDate = new Date(nowYear, lastMonth, 1);
return formatDate(lastMonthStartDate);
}
//获得上月结束时间
function getLastMonthEndDate() {
var lastMonthEndDate = new Date(nowYear, lastMonth, getMonthDays(lastMonth));
return formatDate(lastMonthEndDate);
}
//获得本季度的开始日期
function getQuarterStartDate() {
var quarterStartDate = new Date(nowYear, getQuarterStartMonth(), 1);
return formatDate(quarterStartDate);
}
//或的本季度的结束日期
function getQuarterEndDate() {
var quarterEndMonth = getQuarterStartMonth() + 2;
var quarterStartDate = new Date(nowYear, quarterEndMonth,
getMonthDays(quarterEndMonth));
return formatDate(quarterStartDate);
}
js 计算月/周的第一天和最后一天
因为项目开发中遇到需要向后台传本周的开始和结束时间，以及上一周的起止时间，就琢磨了半天，总算写出来一套，写篇文章是为了方便自己记忆，也是分享给需要的人，水平有限，写的不好请见谅：
getDateStr3函数是为了把时间对象转变为yy-mm-dd的字符串，方便传值；
getWeekStartAndEnd函数是获取周的起止时间，并且用getDateStr3转换成字符串放到数组中，其中参数0代表当前周，-1代表前一周，-2代表上上周，以此类推，反过来也可以1代表下一周；
getMonthStartAndEnd函数是获取月的起止时间，传参同上
//获取当前日期yy-mm-dd //date 为时间对象 function getDateStr3(date) { var year = ""; var month = ""; var day = ""; var now = date; year = ""+now.getFullYear(); if((now.getMonth()+1)<10){ month = "0"+(now.getMonth()+1); }else{ month = ""+(now.getMonth()+1); } if((now.getDate())<10){ day = "0"+(now.getDate()); }else{ day = ""+(now.getDate()); } return year+"-"+month+"-"+day; } /** * 获得相对当前周AddWeekCount个周的起止日期 * AddWeekCount为0代表当前周 为-1代表上一个周 为1代表下一个周以此类推 * **/ function getWeekStartAndEnd(AddWeekCount) { //起止日期数组 var startStop = new Array(); //一天的毫秒数 var millisecond = 1000 * 60 * 60 * 24; //获取当前时间 var currentDate = new Date(); //相对于当前日期AddWeekCount个周的日期 currentDate = new Date(currentDate.getTime() + (millisecond * 7*AddWeekCount)); //返回date是一周中的某一天 var week = currentDate.getDay(); //返回date是一个月中的某一天 var month = currentDate.getDate(); //减去的天数 var minusDay = week != 0 ? week - 1 : 6; //获得当前周的第一天 var currentWeekFirstDay = new Date(currentDate.getTime() - (millisecond * minusDay)); //获得当前周的最后一天 var currentWeekLastDay = new Date(currentWeekFirstDay.getTime() + (millisecond * 6)); //添加至数组 startStop.push(getDateStr3(currentWeekFirstDay)); startStop.push(getDateStr3(currentWeekLastDay)); return startStop; } /** * 获得相对当月AddMonthCount个月的起止日期 * AddMonthCount为0 代表当月 为-1代表上一个月 为1代表下一个月 以此类推 * ***/ function getMonthStartAndEnd(AddMonthCount) { //起止日期数组 var startStop = new Array(); //获取当前时间 var currentDate = new Date(); var month=currentDate.getMonth()+AddMonthCount; if(month<0){ var n = parseInt((-month)/12); month += n*12; currentDate.setFullYear(currentDate.getFullYear()-n); } currentDate = new Date(currentDate.setMonth(month)); //获得当前月份0-11 var currentMonth = currentDate.getMonth(); //获得当前年份4位年 var currentYear = currentDate.getFullYear(); //获得上一个月的第一天 var currentMonthFirstDay = new Date(currentYear, currentMonth,1); //获得上一月的最后一天 var currentMonthLastDay = new Date(currentYear, currentMonth+1, 0); //添加至数组 startStop.push(getDateStr3(currentMonthFirstDay)); startStop.push(getDateStr3(currentMonthLastDay)); //返回 return startStop; }