<section id="app" class="container pt-5">
  <label for="">Enter a date</label>
  <input type="text" class="datepicker form-control" v-model="value" >  
  <hr />
  
  <p>Date is: {{ value }}</p>
  
</section>
var app = new Vue({
  el: '#app',
  data: {
    value: '02/02/1988'
  }
})

//var regex = /(0[1-9]|[12][0-9]|3[01])[- /.](0[1-9]|1[012])[- /.](19|20)\d\d/
//var regex = /^(0[1-9]|[12][0-9]|3[01])|(0[1-9]|1[012])/
var regex = /^(0[1-9]|1[012]|[1-12])(|\/|\.)(0[1-9]|[12][0-9]|3[01]|[1-9])(|\/|\.)(((19|20)\d\d)|(\d\d)$)/gm

function ExtractDate(date){
  if (typeof(date)==="object") return date;
  var a = regex.exec(date);
  if (!a) return;
         
  var mm = +a[1], dd = +a[3], yy = +a[5];
  mm = mm < 10 ? "0" + mm : mm; 
  dd = dd < 10 ? "0" + dd : dd;
  yy = yy.toString().length === 4 ? yy : 30 < yy && yy < 100 ? 1900+yy : 2000+yy

  
  return {
    mm: mm,
    dd: dd,
    yy: yy,
    date: new Date(+yy, (+mm - 1), (+dd) )
  };
}
  
$(".datepicker").datepicker({
  format: {
    /*
     * Say our UI should display a week ahead,
     * but textbox should store the actual date.
     * This is useful if we need UI to select local dates,
     * but store in UTC
     */
    toDisplay: function(date, format, language) {
      console.log('>' , date )
      if (typeof(date)==="object") {
        var mm = date.getMonth() + 1, dd =  date.getDate(), yy = date.getFullYear();
        mm = mm < 10 ? "0" + mm : mm; 
        dd = dd < 10 ? "0" + dd : dd;        
      } 
      console.log('>>', date, mm, dd, yy)
      return [mm, dd, yy].join("/");
      /*return date;
      var d = ExtractDate(date);
      console.log("toDisplay:", date, d, typeof(date));
      if (!d) return
      var result = [d.dd, d.mm, d.yy].join("\\")
      console.log("toDisplay:", d, result);
      return result; */
    },
    toValue: function(date, format, language) {
      console.log('+', date)
      var d = ExtractDate(date)
      if (!d) return
      console.log("toValue:", d );
      return d.date;
    }
  }
});

External CSS

  1. https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0/css/bootstrap.css
  2. https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datepicker/1.7.1/css/bootstrap-datepicker3.css

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js
  2. https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0/js/bootstrap.min.js
  3. https://cdnjs.cloudflare.com/ajax/libs/bootstrap-datepicker/1.7.1/js/bootstrap-datepicker.js
  4. https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.13/vue.min.js