In Regulation 93 we can find the special time limits for declarations of ineffectiveness of contracts that have been awarded. As with Regulation 92, the drafting is slightly convoluted and it contains different triggers to start the time limit.
According to paragraphs 2 to 5, the 30 day time limits start to count if any of these happens:
i) award notice is published;
ii) contract conclusion was notified to the economic operator.
The first ground only applies if the contract award notice was published in the Official Journal and referred to a contract that was awarded without a prior publication of a contract notice and the contract award notice includes justification of the decision to award the contract. This raises a big issue of discoverability as the "obligation" of publishing contract award notices in the Official Journal is seldom complied with. In consequence it may be pretty much impossible to know a contract without prior publication of notice was ever awarded. Additionally, paragraph 2 caps the duration of the time limit period to a maximum of 6 months "from the date the contract was entered into".
The second ground applies to contracts awarded under other procedures where a standstill period was issued or even if not complied with, at least the contracting authority has provided a summary "of the relevant reasons" as required by Regulation 55(2). Contrary to Regulation 92 however, the trigger to start the time limit is not the sending of the information but its actual receipt. The same caveat as with the first ground aboce remains however: what happens if the contracting authority does not comply with this requirement of providing the relevant reasons? In any case the 6 month cap will always be in place.