2.1.5 Converters
Converters do the job converting object and scalar values into strings. They also handle the task of localization. The sample below declares a DateTime converter for an HtmlOutputText component:
<h:outputText value="#{user.dateOfBirth}">
<f:convert_datetime type="both" dateStyle="full" />
</h:outputText>
"JSF ships with converters for common types like dates and numbers, but you or third parties, can develop additional ones as well."