private static final Set<String> ORDINALS = new HashSet<String>();

    private static final Map<String, Integer> ORDINAL_TO_WEEK_NUMBER_MAPPING = new HashMap<String, Integer>();

    static {
        ORDINALS.add("1st");
        ORDINALS.add("2nd");
        ORDINALS.add("3rd");
        ORDINALS.add("4th");
        ORDINALS.add("5th");
        ORDINALS.add("last");

        ORDINAL_TO_WEEK_NUMBER_MAPPING.put("1st", 1);
        ORDINAL_TO_WEEK_NUMBER_MAPPING.put("2nd", 2);
        ORDINAL_TO_WEEK_NUMBER_MAPPING.put("3rd", 3);
        ORDINAL_TO_WEEK_NUMBER_MAPPING.put("4th", 4);
        ORDINAL_TO_WEEK_NUMBER_MAPPING.put("5th", 5);

    }