js根据日期获取所在周

function getFirstLastDay (time) {

let date = new Date(time)
let Time = date.getTime()
let day = date.getDay()
let oneDayTime =24*60*60*1000 //周一
let MondayTime = Time - (day - 1) * oneDayTime
//周日
let SundayTime = Time + (7 - day) * oneDayTime let monday =new Date(MondayTime)
let sunday = new Date(SundayTime)

return { monday, sunday }
}

function getFirstDay (date) {
let day =date.getDay() || 7

return new Date(date.getFullYear(), date.getMonth(), date.getDate() + 1 - day)
}

function getLastDayOf (date) {
let day = date.getDay() || 7

return new Date(date.getFullYear(), date.getMonth(), date.getDate() + 7 - day)
}