After 2016 blocks have been found, how is the difficulty adjusted to make finding blocks slower/faster... I thought timestamps were used for this.
There are timestamps in blocks, that is used to compute the difficulty change (and blocks must be within 2 hours of network mean time or will be rejected by other nodes).
However that has nothing to do with this transaction. There are no timestamps on transactions. Blockchain.info is simply (incorrectly) reporting the time THEY saw the transaction which even if correct will vary from node to node.