element日期控件修改时候显示1970年的问题

记录下element日期控件修改时候显示1970年的问题，新增时候正常。

因为DatePicker 日期选择器不支持字符串，只支持时间格式

        //修改
        openEditDia(data) {
            let yearDate = new Date();
            yearDate.setYear(data.year);
            this.addQuery.id = data.id,
            this.addQuery.year = yearDate, //把年份处理下再赋给绑定的年份
            this.addQuery.orgName = data.orgName,
            this.addQuery.orgId = data.orgId;
            this.addQuery.dockingPeople = data.dockingPeople
            this.addQuery.dockingPeopleName = data.dockingPeopleName,
            this.addQuery.conference = data.conference,
            this.addQuery.participant = data.participant,
            this.addQuery.organization = data.organization,
            this.addQuery.contac = data.contac,
            this.addQuery.remark = data.remark,
            this.dialogTitle = '《高端对接清单》'
            this.addDialogVisible = true
            this.editFlag = true;
            console.log(this.addQuery.year, '年份')
            this.jsId = data.orgId;
            this.getPerson()
        },