获取上月时间

// 获取上月时间
    getLastMonth(value){
        // if(value==''|| value==undefined){
        //     return value
        // }
        // if(value.length==10){
        //     value = value *1000
        // }
        value = new Date(value)
        // let myDate = new Date(value.getTime() - 7 * 24 * 3600 * 1000)
        // 获取上个月时间
        let nowdays = new Date(value.getTime())
        let year = nowdays.getFullYear()
        let month = nowdays.getMonth()
        if (month === 0) {
            month = 12
            year = year - 1
        }
        if (month < 10) {
            month = '0' + month
        }
        let yDate = new Date(year, month, 0)
        let startDateTime = year + '-' + month + '-01' //上个月第一天
        let endDateTime = year + '-' + month + '-' + yDate.getDate() //上个月最后一天
        return {
            startDateTime:startDateTime,
            endDateTime:endDateTime
        }
    }