1. The customs authorities shall specify the period within which the inward-processing procedure is to be discharged, in accordance with Article 138. That period shall run from the date on which the non-Community goods are placed under the procedure and shall take account of the time required to carry out the processing operations and to discharge the procedure.
2. The customs authorities may grant an extension, of reasonable duration, of the period specified pursuant to paragraph 1, on submission of a duly justified request by the holder of the authorisation. The authorisation may specify that a period which commences in the course of a calendar month, quarter or semester shall end on the last day of a subsequent calendar month, quarter or semester respectively.
3. In cases of prior exportation in accordance with Article 142(2)(b), the customs authorities shall specify the period within which the non-Community goods must be declared for the procedure. That period shall run from the date of acceptance of the export declaration relating to the processed products obtained from the corresponding equivalent goods.