SOURCE

let date =  '2021年11月'
// console.log(`${date.split('年')[0]}-${date.split('年')[1].split('月')[0]}`)
date = `${date.split('年')[0]}-${date.split('年')[1].split('月')[0]}`

console.log(date)


let date1 = '2021-04-08'
// console.log(date1.slice(0,7))



let obj = [
    {
        date:'2021-10-20'
    },
     {
        date:'2021-11-20'
    },
     {
        date:'2021-11-20'
    }
]


obj = obj.filter( item => item.date.slice(0,7) ===  date)


console.log(obj)