The date isn't the date of confirmation I don't believe. I believe it is the date the transaction was received by the node.
Each raw TX includes a 'received' and a 'relayed_by' field that indicates when the transactions was received and what IP relayed it. You can decode a raw transaction to see this information so it is included in the transaction itself. This is present even in unconfirmed transactions and everyone should see the same date for a transaction.
Raw transaction doesn't have all of those. Try looking at one[1].
If it's the date when the transaction was received by the node, people will see varied dates depending on when their node/server received the transaction.
And no, I've compared the dates of multiple transactions with the blocktime of the blocks that they were included in. They all match.
[1]
https://blockchain.info/tx/8514258f73e707f64585aa9fce974dce99994e62692a4451a621f3dacaf37ccf?format=hex{
"lock_time":0,
"size":225,
"inputs":[
{
"prev_out":{
"index":1,
"hash":"f4621217add356ad0ae1ddeecddc24a236aeef73dec80a65430bfd584560c797"
},
"script":"47304402207db793e1674c73cd02f88c977c220076483cf56def726bfaaa0d5b25ef4c27e1022061bfddbd21b57a26a1b608f9a53883800c6e04a88dbadebafec622d1b6845bef0121024b62c14291a74aa8b800bff4b269342d14a1b06ec5029d5e62eae2111c97f342"
}
],
"version":1,
"vin_sz":1,
"hash":"8514258f73e707f64585aa9fce974dce99994e62692a4451a621f3dacaf37ccf",
"vout_sz":2,
"out":[
{
"script_string":"OP_DUP OP_HASH160 c570307825ee31ab46043fd96f586e71b51a5f25 OP_EQUALVERIFY OP_CHECKSIG",
"address":"1JzxWqqvFbns95BoR1M9vzRoTWLr5qDaFJ",
"value":4830918,
"script":"76a914c570307825ee31ab46043fd96f586e71b51a5f2588ac"
},
{
"script_string":"OP_DUP OP_HASH160 27604a5e30f59c7bc86c39fc4003542089085133 OP_EQUALVERIFY OP_CHECKSIG",
"address":"14bChs2nPdL4jMhsQvCWk2XSSGiMdt4U6d",
"value":1210615320,
"script":"76a91427604a5e30f59c7bc86c39fc400354208908513388ac"
}
]
}