I do not know about JAR but FAA rules say that you can fly with an out of date data as long as you can verify every single way point via an uptoday navigation chart. As far as I know also ICAO rules also allow you to do the say with the say requirement. I fly in India and with the new hydraban airport opening delay for two weeks. We were required to use the expire data when flying that route as per notac.
Hope it help.....
