I have a property field in a class that is of type javax.xml.datatype.Duration. It basically represents a time span (e.g. 4 hours and 34 minutes).
javax.xml.datatype.Duration
JPA
You could try joda-time hibernate. Refer to the available types that can be persisted. You could then use the joda Duration in the following way:
@Type(type="org.joda.time.contrib.hibernate.PersistentDuration") private Duration startDateTime;