Green date format or 2018-08-08 format converted to 20180808 format

/* Conversion date: 20180808 */
        transformData (date) {
            let _date = new Date(date)
            let m = (_date.getMonth() + 1) < 10 ? '0' + (_date.getMonth() + 1) : (_date.getMonth() + 1)
            let d = _date.getDate() < 10 ? '0' + _date.getDate() : _date.getDate()
             let _result = _date.getFullYear() + '' + m + '' + d;
            return _result
        }

Get the date n days ago and convert to 2018-08-08 format

/* Get date n days ago */
        getDate () {
            let myDate = new Date()；
            let dateNow = new Date(myDate - 1000 * 60 * 60 * 24 * n);
            let nowY = dateNow.getFullYear();
            let nowM = dateNow.getMonth() + 1;
            let nowD = dateNow.getDate();
            let enddate = nowY + '' + (nowM < 10 ? '0' + nowM : nowM) + '' + (nowD < 10 ? '0' + nowD : nowD);
            return enddate
        }

Calculate the number of days between two dates (green date or 2018-08-08 date format)

/* Calculate days between two dates */
        daysBetween (date1, date2) {
            var aDate = new Date(date1)
            var bDate = new Date(date2)
            var aDay = 24 * 60 * 60 * 1000;
            var diffDay = (bDate - aDate) / aDay
            return diffDay
        },

Compare the size of two dates (date format is 2018-01-01 or green date format)

/* Calculate the size of two dates date1 is greater than date2 return - 1 */
        tab (date1, date2) {
            var oDate1 = new Date(date1)
            var oDate2 = new Date(date2)
            if (oDate1.getTime() > oDate2.getTime()) {
                return -1
            } else {
                return 0
            }
        },

Get the date of the previous month and the previous 13 months, or the date of the previous day and the previous 31 days

/* Obtain the dates of the previous month and the previous 13 months or the previous day and the previous 31 days */
        getDate (type) {
            if (type === 'm') {
                let dEnd = new Date()
                // Get previous month date
                let yEnd = dEnd.getFullYear()
                let mEnd = dEnd.getMonth();
                mEnd = ((mEnd === 0) ? (12) : (mEnd));
                mEnd = mEnd < 10 ? '0' + mEnd : mEnd;
                // Date before acquisition 13 months ago
                let yStart = dEnd.getFullYear() - 1
                return {start: yStart + '-' + mEnd, end: yEnd + '-' + mEnd}
            } else if (type === 'd') {
                let myDate = new Date();
                //  Get one day date
                let dateNow = new Date(myDate - 1000 * 60 * 60 * 24 * 1);
                let nowY = dateNow.getFullYear();
                let nowM = dateNow.getMonth() + 1;
                let nowD = dateNow.getDate();
                let enddate = nowY + '-' + (nowM < 10 ? '0' + nowM : nowM) + '-' + (nowD < 10 ? '0' + nowD : nowD);
                // Get 31 day date
                let dateLast = new Date(myDate - 1000 * 60 * 60 * 24 * 30);
                let lastY = dateLast.getFullYear();
                let lastM = dateLast.getMonth() + 1;
                let lastD = dateLast.getDate();
                let startdate = lastY + '-' + (lastM < 10 ? '0' + lastM : lastM) + '-' + (lastD < 10 ? '0' + lastD : lastD);
                return {start: startdate, end: enddate}
            }
        },