Date-time selected date custom backgroundImage

Ionic Framework Ionic Angular
1

In date-time component we need a custom style setting for selected date background image:

In the highlighted dates module, the my json is:

    this.highlightedDates = \[

      {

        date: '2025-09-04',

        textColor: '#800080',

        backgroundColor: "var(--ion-color-tertiary)",

        cssClass: 'fire-day',

      },

    \];

CSS:
.fire-day{

background-image: url(“/streak/fire.svg”);

background-size: contain;

background-repeat: no-repeat;

background-position: center;

border: 1px solid #e91e63;

color: #800080; /* keeps the date text */

}

How to set the custom CSS class if i need to set a background image for the selected date?