title: vuejs getting the value of a datepicker after selected
body: <p>in vue js i want to get the result of 2 date-picker and get the different days between them but problem is i want to do it before form is submitted i mean when the user select dates i want to count the days and give price according to it i use a persian date picker i add it below if it may help :</p>
  
  <pre><code>https://github.com/talkhabi/vue-persian-datetime-picker
  </code></pre>
  
  <p>and here is my html markup :</p>
  
  <pre><code>&lt;div class="row"&gt;
                  &lt;div class="col-lg-6"&gt;
                      &lt;label&gt;start reserve&lt;/label&gt;
                      &lt;date-picker :auto-submit="true" v-model="date" :max="available_end.toString()"
                                   :min="reserve_end.toString()"&gt;&lt;/date-picker&gt;
                  &lt;/div&gt;
                  &lt;div class="col-lg-6"&gt;
                      &lt;label&gt;end reserve&lt;/label&gt;
                      &lt;date-picker :auto-submit="true" v-model="date2" :max="available_end.toString()"
                                   :min="reserve_end.toString()"&gt;&lt;/date-picker&gt;
                  &lt;/div&gt;
              &lt;/div&gt;
  </code></pre>
  
  <p>and here is the vuejs part :</p>
  
  <pre><code>data(){
  return {
  date: '',
  date2:'',
  }
  },
   components: {
          datePicker: VuePersianDatetimePicker
      },
  </code></pre>
  
  <p>the code contains much more so i cut it for better reading  and
  i tried to use the date and date2 but they dont seem to work . </p>