Get composite component inputs' converted values

Question

I have a composite component made of two p:calendars:

<cc:interface componentType="testComponent">
    <cc:attribute name="value" type="org.primefaces.test.DateRange" />
</cc:interface>

<cc:implementation>
    <c:set value="dd-MM-yyyy" var="pattern" />

    <p:panelGrid columns="2">
        <p:outputLabel for="from" value="From" />
        <p:calendar id="from" binding="#{cc.from}" pattern="#{pattern}" />

        <p:outputLabel for="to" value="To" />
        <p:calendar id="to" binding="#{cc.to}" pattern="#{pattern}" />
    </p:panelGrid>

</cc:implementation>

Class DateRange:

public class DateRange {

private Date from;
private Date to;

public DateRange() {
}

public DateRange(Date from, Date to) {
    this.from = from;
    this.to = to;
}

public Date getFrom() {
    return from;
}

public void setFrom(Date from) {
    this.from = from;
}

public Date getTo() {
    return to;
}

public void setTo(Date to) {
    this.to = to;
}

@Override
public String toString() {
    return from + " --> " + to;
}
}

Backing class:

@FacesComponent("testComponent")

public class TestComponent extends UIInput implements NamingContainer {

private UIInput from;
private UIInput to;
private static final String DELIMITER = "-->";

@Override
public String getFamily() {
    return UINamingContainer.COMPONENT_FAMILY;
}

@Override
public void encodeBegin(FacesContext context) throws IOException {
    DateRange range = (DateRange) getValue();
    System.out.println(range);
    if (range != null) {
        from.setValue(range.getFrom());
        to.setValue(range.getTo());
    }
    super.encodeBegin(context);
}

@Override
public Object getSubmittedValue() {
    if (from == null || to == null) return null;

    String submittedFrom = (String) from.getSubmittedValue();
    String submittedTo = (String) to.getSubmittedValue();

    if (submittedFrom == null) {
        submittedFrom = "";
    }
    if (submittedTo == null) {
        submittedTo = "";
    }

    return submittedFrom + DELIMITER + submittedTo;
}

@Override
protected Object getConvertedValue(FacesContext context, Object newSubmittedValue) throws ConverterException {
    String submitted = (String) newSubmittedValue;
    if (submitted == null || submitted.isEmpty()) {
        return null;
    }

    String[] split = submitted.split(DELIMITER);

    String fromStr = split.length > 0 ? split[0] : "";
    String toStr = split.length > 1 ? split[1] : "";

    // TODO: Do I need to perform a manual conversion of the inputs???

    return new DateRange((Date) fromObj, (Date) toObj);
}

getConvertedValue() should return an instance of DateRange. To get dates from calendars, I would need to call getConvertedValue() on each but this method is protected and I cannot access it.

Do I need to manually get the pattern from the p:calendar and convert the value myself? If yes, how do I even know how the conversion is really done in Calendaritself? I wonder how is this approached in more complex components where conversion on subcomponents is not that trivial.