js 獲取當前日期任意天數的日期 任意月份的起止日期

// 根據周一的日期獲取周日的日期

let time = new Date();

let y = time.getFullYear();

let m = time.getMonth() + 1;

let d = time.getDate();

let date2 = y + '-' + m + '-' + d;

let weekEnd;

getWeeklast(6,date2);

function getWeeklast(num, weekStart) {

let newDate = time;

newDate.setDate(newDate.getDate() + num);

let y = newDate.getFullYear();

let m = newDate.getMonth() + 1;

let d = newDate.getDate();

let date1 = y + '-' + m + '-' + d;

weekEnd = date1;

}

console.log('當前時間' + date2);

console.log('一周后時間'+ weekEnd);

// 獲取一個月的開始時間和結束時間

let monthStart;

let monthEnd;

getMonthStartEndDay(y,m);

function getMonthStartEndDay(year,month){

let startDay = new Date(year,month,1);

monthStart = y + '-' + m + '-' + startDay.getDate();

let endDay = new Date(startDay.getTime() - 1000 * 60 * 60 * 24).getDate();

monthEnd = y + '-' + m + '-' + endDay;

}

console.log('當前月初的時間' + monthStart);

console.log('當前月末的時間' + monthEnd);