title: How can I multiple datepicker modal in vuetify?
body: <p>My vue component like this : </p>
  
  <pre><code>&lt;template&gt;
    &lt;v-row&gt;
      &lt;v-col cols="12" sm="6" md="4"&gt;
        &lt;v-dialog
          v-for="(item, i) in test" :key="i"
          ref="dialog"
          v-model="modal"
          :return-value.sync="item.date"
          persistent
          width="290px"
        &gt;
          &lt;template v-slot:activator="{ on }"&gt;
            &lt;v-text-field
              v-model="item.date"
              label="Picker in dialog"
              prepend-icon="event"
              readonly
              v-on="on"
            &gt;&lt;/v-text-field&gt;
          &lt;/template&gt;
          &lt;v-date-picker v-model="date" scrollable&gt;
            &lt;div class="flex-grow-1"&gt;&lt;/div&gt;
            &lt;v-btn text color="primary" @click="modal = false"&gt;Cancel&lt;/v-btn&gt;
            &lt;v-btn text color="primary" @click="$refs.dialog.save(item.date)"&gt;OK&lt;/v-btn&gt;
          &lt;/v-date-picker&gt;
        &lt;/v-dialog&gt;
      &lt;/v-col&gt;
    &lt;/v-row&gt;
  &lt;/template&gt;
  
  &lt;script&gt;
    export default {
      data: () =&gt; ({
        test: [
          { id: 1, date: new Date().toISOString().substr(0, 10) },
          { id: 2, date: new Date().toISOString().substr(0, 10) },
        ],
        modal: false,
      }),
    }
  &lt;/script&gt;
  </code></pre>
  
  <p>multiple datetimepicker doesn't work properly</p>
  
  <p>if i click ok button in the modal, there exist error like this :</p>
  
  <p>[Vue warn]: Error in v-on handler: "TypeError: _vm.$refs.dialog.save is not a function"</p>
  
  <p>How can I solve this problem?</p>