protected Date getReferenceDate() throws IOException {
        Date referenceDate = EnvUtil.loadTimestamp(getBuildTimestampFile());
        return referenceDate != null ? referenceDate : new Date();
    }
protected Date getReferenceDate ( ) throws IOException { Date referenceDate = EnvUtil . loadTimestamp ( getBuildTimestampFile ( ) ) ; return referenceDate != null ? referenceDate : new Date ( ) ; }
from an existing build date file. If this does not exist, the current date is used.