<div *ngFor="let eventChunks of chunks(events,3);">
      <div *ngFor="let event of eventChunks" class="card-columns">
        <event-item [event]="event"></event-item>
      </div>

chunks(array, size) {
        let results = [];
        results = [];
        while (array.length) {
            results.push(array.splice(0, size));
        }
        return results;
    };

ERROR Error: ExpressionChangedAfterItHasBeenCheckedError: Expression has changed after it was checked. Previous value: 'ngForOf: [object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]'. Current value: 'ngForOf: '.