def add_countdown_in(date, event, events_dates_per_event):
    """
    Given a date and an even,
    compute the number of days until the next occurence of this events within events_dates_per_event
    """
    countdown = []
    for special_date in events_dates_per_event[event]:
        date_count_down = (special_date - date).days
        if date_count_down >= 0:
            countdown.append(date_count_down)

    return min(countdown)