时间格式：

            <el-time-picker 
                is-range
                v-model="form.timePoint" 
                format = 'HH:mm' 
                value-format = 'HH:mm:ss' 
                range-separator="至"
                placeholder="选择时间范围">
            </el-time-picker>


            timePoint : ['06:00:00', '23:00:00']

时间戳格式

          <el-time-picker
            is-range
            v-model="form.timePoint"
            format="HH:mm:ss"
            value-format="timestamp"
            range-separator="至"
            start-placeholder="开始时间"
            end-placeholder="结束时间"
            placeholder="选择时间范围"
          >
          </el-time-picker>

           timePoint = [1618178400000, 1618239600000]