el-form 表单设置某个参数非必填验证

          <el-date-picker
            v-if="tabsActive === 0"
            :clearable="false"
            v-model="yearValue"
            @change="yearTimeChange"
            type="year"
            placeholder="选择年"
            value-format="yyyy"
            :picker-options="pickerOptions"
            style="width: 90px; border-radius: 8px"
          >
          </el-date-picker>


  data () {
    return {
      pickerOptions: {
        disabledDate (time) {
          return time.getFullYear() < new Date().getFullYear()
        }
      },
    }
  }

 2、禁止选择今天之前的所有日期

          <el-date-picker
              style="width: 230px"
              v-model="countryTime"
              type="monthrange"
              range-separator="至"
              start-placeholder="开始月份"
              end-placeholder="结束月份"
              value-format="yyyy-MM"
              size="small"
              :clearable="false"
              :picker-options="pickerOptions"
              @change="monthrangeChange($event, 1)"
            >
            </el-date-picker>


  data () {
    return {
      minDate: null,
      maxDate: null,
      pickerOptions: {
        disabledDate: (time) => {
          if (this.minDate !== null && this.maxDate === null) {
            let minMonth = this.minDate.getMonth(),
              lastYear = new Date(this.minDate).setMonth(minMonth - 17),
              nextYear = new Date(this.minDate).setMonth(minMonth + 17)
            // 只能选 minDate 前后18个月的范围
            return time.valueOf() < lastYear.valueOf() || time.valueOf() > nextYear.valueOf()
          }
          return false
        },
        onPick: ({ minDate, maxDate }) => {
          this.minDate = minDate
          this.maxDate = maxDate
        }
      },
    }
  }

            

 
data(){
  return{
    deadlineTime:'2023-11-20'  //  代表指定日期
    pickerOptions: {
        disabledDate(v) {
          return v.getTime() < new Date(deadlineTime || new Date()).getTime(); 
        },
      },
  }
}