get set typescript properties

some.model.ts

   // Format conversions
    get _startDate() {

        if (this.startDate) {

            let d = new Date(this.startDate);
            return d.toLocaleDateString();
        }

        return '';
    }

    set _startDate(value) {
        if (value) {
            let d = new Date(value);
            let utcDate = new Date(Date.UTC(d.getFullYear(), d.getMonth(), d.getDate(), 0, 0, 0))
            this.startDate = utcDate.toJSON();
        }
    }