ngbDatepicker set value

In my Angular application, template driven form, I have a date of birth field and added ngbDatepicker for that field as given.

<input #dob="ngbDatepicker"
                 (click)="dob.toggle()"
                 [(ngModel)]="model.dob"
                 [ngClass]="{ 'is-invalid': f.submitted &&  dob.invalid }"
                 class="form-control"
                 id="dob"
                 name="dob"
                 required
                 type="text"
                 [disabled]="isDisabled"
                 [class.ash]="isDisabled"
                 [class.highlight]="!isDisabled"
                 ngbDatepicker
          />

I'm getting date of birth form back-end API as dob: "2019-02-16 00:00:00" and I want to pass that value like bellow,

 { 
  "year": 2019, 
  "month": 2, 
  "day": 26 
 }

because ngbDatepicker get value in that format. This is what I tried to convert my date of birth.

toDate(dob) {
 const [year, month, day] = dob.split('-');
 const obj = { year: year, month: month, day: day.split(' ')[0].trim() };
 console.log('convert date', obj);
 this.model.dob = obj;
 //  this.model.dob ={year: 2017, month: 5, day: 13};
}

The output is {year: "2019", month: "02", day: "16"} , I want to remove quotation marks from this output. I've tried so many methods and unable to get the needed output. I could get {"year": 2019, "month": 02, "day": 16} this output using bellow code.

JSON.stringify({ "year": "2019", "month": "2", "day": "26" }, (key, value) => !isNaN(+value) ? +value : value);

But to set the date I need to set object like this. {year: 2019, month: 2, day: 26 }

I could resolve my problem using 'parseInt'.Use this link to know more about parseInt. I changed my code as given bellow.

toDate(dob) {
if (dob) {
  const [year, month, day] = dob.split('-');
  const obj = { year: parseInt(year), month: parseInt(month), day: 
    parseInt(day.split(' ')[0].trim()) };
  this.model.dob = obj;
  }
}