Ionic 2: Add Class to Item While Removing Class From Other Items

I have a div full of buttons that, when clicked, should add a class (selected-date-item) that changes the color of the button. Immediately before that, I want to remove that class (selected-date-item) from any button that previously held that class.

CSS

.selected-date-item {
  background:#272829;
  color:white;
}

HTML

<button class="date-time-select" *ngFor="let chooseDate of possibleDates" (tap)="selectPickupDate(chooseDate)">{{chooseDate}}</button>

JS

selectPickupDate(selectedDate) {
  this.selectedDate = selectedDate;
}

=>