js 根据年月,周获取周一至周日的日期 以周期为日期

获取每月有几周
function getWeeks(year, month) {//year年 month月
var d = new Date();
// 该月第一天
d.setFullYear(year, month-1, 1);
var w1 = d.getDay();
if (w1 == 0) w1 = 7;
// 该月天数
d.setFullYear(year, month, 0);
var dd = d.getDate();
// 第一个周一
let d1;
if (w1 != 1) d1 = 7 - w1 + 2;
else d1 = 1;
let week_count = Math.ceil((dd-d1+1)/7);
return week_count;
}
根据年月周获取该周从周一到周日的日期
function getWeekTime(year, month,weekday) {//year年 month月 weekday第几周
var d = new Date();
// 该月第一天
d.setFullYear(year, month-1, 1);
var w1 = d.getDay();
if (w1 == 0) w1 = 7;
// 该月天数
d.setFullYear(year, month, 0);
var dd = d.getDate();
// 第一个周一
let d1;
if (w1 != 1) d1 = 7 - w1 + 2;
else d1 = 1;
var monday = d1+(weekday-1)7;
var sunday = monday + 6;
var from = year+"-"+month+"-"+monday;
var to;
if (sunday <= dd) {
to = year+"-"+month+"-"+sunday;
} else {
d.setFullYear(year, month-1, sunday);
let days=d.getDate();
to = d.getFullYear()+"-"+(d.getMonth()+1)+"-"+days;
}
console.log(weekday+" 从" + from + " 到 " + to + “”);
}
获取每月第几周的周一的日期
function getMondayTime(year, month,weekday) {
var d = new Date();
// 该月第一天
d.setFullYear(year, month-1, 1);
var w1 = d.getDay();
if (w1 == 0) w1 = 7;
// 该月天数
d.setFullYear(year, month, 0);
var dd = d.getDate();
// 第一个周一
let d1;
if (w1 != 1) d1 = 7 - w1 + 2;
else d1 = 1;
var monday = d1+(weekday-1)7;
return monday;
}
获取周一的日期
function getMonDate() {
var d=new Date(),
day=d.getDay(),
date=d.getDate();
if(day1)
return d;
if(day0)
d.setDate(date-6);
else
d.setDate(date-day+1);
return d;
}
获得周期名字
function getDayName(day) {
var day=parseInt(day);
if(isNaN(day) || day<0 || day>6)
return false;
var weekday=[“周日”,“周一”,“周二”,“周三”,“周四”,“周五”,“周六”];
return weekday[day];
}
获得当前日期在当月第几周
//不包括跟上个月重合的部分
function getMonthWeek(a, b, c) {
var date = new Date(a, parseInt(b) - 1, c), w = date.getDay(), d = date.getDate();
return Math.ceil(
(d + 6 - w) / 7
);
}
获取当月最后一天日期
function getLastDay(year,month) {
var new_year = year; //取当前的年份
var new_month = month++;//取下一个月的第一天，方便计算（最后一天不固定）
if(month>12) {
new_month -=12; //月份减
new_year++; //年份增
}
var new_date = new Date(new_year,new_month,1); //取当年当月中的第一天
return (new Date(new_date.getTime()-10006060*24)).getDate();//获取当月最后一天日期
}
根据当前日期获取该天所在周，若该月1号不是周一，获取该月第一周的周一日期，小于该日期的归为上个月最后一周
//当前日期几月第几周
function showDate(){
var that=this;
var d=this.getMonDate();
var ds=new Date();
var arr=[];
for(var i=0; i<7; i++) {
let weekDay=this.getDayName(d.getDay());
let date=d.getDate()+‘日’;
if(weekDay==‘周一’){
let beginTime=ds.getFullYear()+’-’+(d.getMonth()+1)+’-’+d.getDate();
that.state.beginTime = beginTime;
}
if(weekDay==‘周日’){
let endTime=ds.getFullYear()+’-’+(d.getMonth()+1)+’-’+d.getDate();
that.state.endTime = endTime;
}
arr.push({weekDay:weekDay,date:date});
d.setDate(d.getDate()+1);
}
let month=ds.getMonth()+1;
let weeks=this.getMonthWeek(ds.getFullYear(),month,ds.getDate())-1;
//每月周一日期
let oneDate=that.getMondayTime(ds.getFullYear(),month,1);
if(ds.getDate()<oneDate){
month=ds.getMonth();
weeks=this.getWeeks(ds.getFullYear(),month);
}
console.log(‘month:’,month,‘weeks:’,weeks);
this.setState({
list:arr,
yearDate:ds.getFullYear(),
monthDate:month,
month:ds.getMonth()+1,
monthWeek:‘第’+weeks+‘周’,
theMonthWeek:‘第’+weeks+‘周’
});
}