SOURCE

let obj = {
    getDate(datestr) {
        let temp = datestr.split('-')
        let date = new Date(temp[0], temp[1] - 1, temp[2])
        return date
    },
    formatEveryDay(start, end, Spacer) {
        
        let dateList = []
        let startTime = this.getDate(start)
        let endTime = this.getDate(end)

        while ((endTime.getTime() - startTime.getTime()) >= 0) {
            let year = startTime.getFullYear()
            let month = startTime.getMonth() + 1 < 10 ? '0' + (startTime.getMonth() + 1) : startTime.getMonth() + 1
            let day = startTime.getDate().toString().length == 1 ? '0' + startTime.getDate() : startTime.getDate()
           
            if (Spacer) {
                // 如果不需要间隔符则直接拼接返回
                if (Spacer === 'null') {
                    dateList.push(year + month + day) // 如20220422,20220423
                } else {
                    // 需要自定义间隔符
                    dateList.push(year + Spacer + month + Spacer + day)
                }
            } else {
                dateList.push(year + '-' + month + '-' + day) // 2022-04-22,2022-04-23
            }
            startTime.setDate(startTime.getDate() + 1)
        }
        return dateList
    }
}

console.log(obj.getDate('2022-01-10')); //"2022-01-09T16:00:00.000Z"

console.log(obj.formatEveryDay('2022-01-10', '2022-01-20'));