Js操作系列获取今天之前四周的筛选

const to = new Date('2020-5-1')
//今天是周几
var todayWeek = to.getDay();
//一天的毫秒数
var oneDayTime = 24 * 60 * 60 * 1000;
//本周周一时间戳
var mondayTime = to.getTime() - (todayWeek - 1) * oneDayTime;
//29天前周一十几号
let after = mondayTime - oneDayTime * 28;
let [arr, cArr] = [[], []];
while (after < mondayTime) {
  if (new Date(after).getDay() === 1 || new Date(after).getDay() === 0) {
    let o = [new Date(after).getFullYear() + '-' + (new Date(after).getMonth() + 1) + '-' + new Date(after).getDate()]
    arr.push(o)
  }
  after += oneDayTime;
}
for (let i = 0; i < arr.length; i += 2) {
  cArr.push(arr.slice(i, i + 2))
}
console.log(cArr)