def get_list_change_date(card, list_before_name, list_after_name):
    """
    Return the date of when a list changed from the specified before & after lists.
    """
    if not card.actions:
        return

    for action in card.actions:
        if all(key in action['data'] for key in ['listBefore', 'listAfter']):
            if action['data']['listBefore']['name'] == list_before_name and action['data']['listAfter']['name'] == list_after_name:
                return action['date']