Ion2-calendar doesn't provide exact year, month, date in case of Range mode

How do i get date like “YYYY-MM-DD” when i clicked on any dates from ion2-calendar.

I have used the below library for calendar,

My HTML code:

<ion-calendar [(ngModel)]="dateRange" [options]="optionsRange" [type]="'string'" [format]="'YYYY-MM-DD'"
              (onChange)="selectedRangeDates($event)" (onSelectStart)="onSelectStart($event)"
              (onSelectEnd)="onSelectEnd($event)" >

My TS Code:

optionsRange: CalendarComponentOptions = {
    pickMode: 'range'

selectedRangeDates(dates) {

onSelectStart(dates) {
    console.log("onSelectStart DATES :: " + JSON.stringify(dates));

onSelectStart DATES ::{"time":1595442600000,"isToday":false,"title":"23","subTitle":"","selected":true,"isLastMonth":false,"isNextMonth":false,"marked":false,"cssClass":"","disable":false,"isFirst":false,"isLast":false}

On the above output i am getting “23” as selected date but instead of 23 i want to get YYYY-MM-DD when on click a single date as start date and dynamically set next 30 days in calendar from the selected date.