如何利用JS获取当前具体日期时间与获取前一天日期时间

Date curDate = new Date();
var nowDate = curDate.getTime();
var preDate = new Date(curDate.getTime() - 24*60*60*1000); //前一天
var nextDate = new Date(curDate.getTime() + 24*60*60*1000); //后一天
//获取前一天具体日期如下
var preDate = new Date(curDate.getTime() - 24*60*60*1000).format("yyyy-MM-dd");
//getTime() 方法可返回距 1970 年 1 月 1 日之间的毫秒数。

 @RequestMapping(value = "/receiveSysDate", method = {RequestMethod.GET})
    @ResponseBody
    public long receiveSysDate() {
        long result = 0L;
        try {
            result = new Date().getTime();
        } catch (Exception e) {
            logger.error(e.getMessage(), e);
        }
        return result;
    }

XX.receiveSyDate = function () {
    var now = null;
    $.ajax({
        type: "get",
        url: $("#path").val() + "/XX/XX/receiveSysDate",
        cache: false,  //禁用缓存
        dataType: "json",
        async: false, // 同步
        success: function (data) {
            now = data;
        },
        error: function (data) {
        }
    });
    return new Date(now);
}

 // 获取当前时间
        var now = XX.receiveSyDate();//Tue Jun 16 2020 15:42:47 GMT+0800 (中国标准时间)
        // 拼接昨天时间
        var yesd = now.getFullYear() + '-' + '0' + (now.getMonth() + 1) + '-' + (now.getDate() - 1);//2020-06-15
        $('.data-range-picker>input:eq(0)').val(this.datetimeUtil.dateFormat(now, "yyyy") + "-01-03");//指定具体的日期
        $('.data-range-picker>input:eq(1)').val(yesd);//指定昨天的日期

if (!window["XX"]) {
    window.XX= {};
}
XX.datetimeUtil = {
    //格式化显示日期时间
    //yyyy年份
    //MM月份
    //dd天
    //hh小时
    //mm分钟
    //ss秒
    dateFormat: function (date, format) {
        if (typeof (date) !== "object" || !date.getFullYear) {
            return;
        }
        var result = format;
        if (format.indexOf("yyyy") > -1) {
            result = result.replace("yyyy", date.getFullYear());
        }
        if (format.indexOf("MM") > -1) {
            result = result.replace("MM",
                shinow.stringUtil.formatLength(date.getMonth() + 1, 2));
        }
        if (format.indexOf("dd") > -1) {
            result = result.replace("dd",
                shinow.stringUtil.formatLength(date.getDate(), 2));
        }
        if (format.indexOf("hh") > -1) {
            result = result.replace("hh",
                shinow.stringUtil.formatLength(date.getHours(), 2));
        }
        if (format.indexOf("mm") > -1) {
            result = result.replace("mm",
                shinow.stringUtil.formatLength(date.getMinutes(), 2));
        }
        if (format.indexOf("ss") > -1) {
            result = result.replace("ss",
                shinow.stringUtil.formatLength(date.getSeconds(), 2));
        }
        return result;
    },
    //根据月份值获取最后一天
    getLastDayByMonth: function (year, month) {
        switch (month) {
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
                return 31;
            case 4:
            case 6:
            case 9:
            case 11:
                return 30;
            case 2:
                return year % 4 === 0 ? 29 : 28;
        }
    },
    getMonDiff: function (startTime, endTime) {
        startTime = new Date(startTime);
        endTime = new Date(endTime);
        var date2Mon;
        var startDate = startTime.getDate() + startTime.getHours() / 24 + startTime.getMinutes() / 24 / 60;
        var endDate = endTime.getDate() + endTime.getHours() / 24 + endTime.getMinutes() / 24 / 60;
        if (endDate >= startDate) {
            date2Mon = 0;
        } else {
            date2Mon = -1;
        }
        return (endTime.getYear() - startTime.getYear()) * 12 + endTime.getMonth() - startTime.getMonth() + date2Mon;
    },
    getMonthBetween: function (startTime, endTime) {
        var result = [];
        var nums = shinow.datetimeUtil.getMonDiff(startTime, endTime);
        startTime = startTime.replace(/-/g, "");
        endTime = endTime.replace(/-/g, "");
        var y1 = parseInt(startTime.substr(0, 4));
        var m1 = parseInt(startTime.substr(4, 2)) - 1;
        var y2 = parseInt(endTime.substr(0, 4));
        var m2 = parseInt(endTime.substr(4, 2)) - 1;
        do {
            var d = new Date(y1, m1++, 1);
            var y = d.getFullYear();
            var m = d.getMonth() + 1;
            var mm = shinow.stringUtil.getDateLength(m);
            var s = y + '-' + mm;
            result.push(s);
        } while (d < new Date(y2, m2, 1));
        var testArray = [];
        if (nums != 0) {
            testArray = result.slice(0, nums);
        } else {
            testArray = result;
        }
        return testArray;
    }
};