For PPL
An applicant shall be deemed to have successfully
completed the theoretical examinations for the
JAR-FCL PPL(A) when awarded a pass in all of
the above examinations within a period of 18
months. A pass will be accepted for the grant of
a JAR-FCL PPL(A) during the 24 months from
the date of successfully completing all of the
theoretical knowledge examinations.
Its similar with the ATPL: 18 months to pass them all but like CAT3C AUTOLAND says, you have
36 months to complete your CPL/IR before the exam credits expire and thats
"from the end of the month of the date of the final pass in the examinations."