The following voting period constants are assuming 9.6 instead of 12 seconds per block. Depending on the sensitivity of lower and upper ranges desired, these may limit or shift the intended settable voting periods. For instance, using the supposed 12 second per block convention, the minimum and maximum settable voting periods should respectively be 7_200 and 100_800. 
https://github.com/nounsDAO/nouns-monorepo/blob/718211e063d511eeda1084710f6a682955e80dcb/packages/nouns-contracts/contracts/governance/NounsDAOLogicV2.sol#L67-L71
