Also, JAA has been limiting any such validation to 1 year.
That same time limitation is in the EASA Cover Regulation - See para 2.
"The period of validation of a licence shall not exceed 1 year, provided
that the basic licence remains valid.
This period may only be extended once by the competent authority that
issued the validation when, during the validation period, the pilot has
applied, or is undergoing training, for the issuance of a licence in
accordance with Part-FCL. This extension shall cover the period of time
necessary for the licence to be issued in accordance with Part-FCL"