rpc: Return block time in getblockchaininfo

doc/release-notes.md

@@ -197,6 +197,8 @@ Low-level changes
 RPC
 ---
 
+- `getblockchaininfo` now returns a new `time` field, that provides the chain tip time. (#22407)
+
 - The RPC server can process a limited number of simultaneous RPC requests.
   Previously, if this limit was exceeded, the RPC server would respond with
   [status code 500 (`HTTP_INTERNAL_SERVER_ERROR`)](https://en.wikipedia.org/wiki/List_of_HTTP_status_codes#5xx_server_errors).

src/rpc/blockchain.cpp

@@ -1425,7 +1425,8 @@ RPCHelpMan getblockchaininfo()
                         {RPCResult::Type::NUM, "headers", "the current number of headers we have validated"},
                         {RPCResult::Type::STR, "bestblockhash", "the hash of the currently best block"},
                         {RPCResult::Type::NUM, "difficulty", "the current difficulty"},
-                        {RPCResult::Type::NUM, "mediantime", "median time for the current best block"},
+                        {RPCResult::Type::NUM_TIME, "time", "The block time expressed in " + UNIX_EPOCH_TIME},
+                        {RPCResult::Type::NUM_TIME, "mediantime", "The median block time expressed in " + UNIX_EPOCH_TIME},
                         {RPCResult::Type::NUM, "verificationprogress", "estimate of verification progress [0..1]"},
                         {RPCResult::Type::BOOL, "initialblockdownload", "(debug information) estimate of whether this node is in Initial Block Download mode"},
                         {RPCResult::Type::STR_HEX, "chainwork", "total amount of work in active chain, in hexadecimal"},
@@ -1481,6 +1482,7 @@ RPCHelpMan getblockchaininfo()
     obj.pushKV("headers",               pindexBestHeader ? pindexBestHeader->nHeight : -1);
     obj.pushKV("bestblockhash",         tip->GetBlockHash().GetHex());
     obj.pushKV("difficulty",            (double)GetDifficulty(tip));
+    obj.pushKV("time",                  (int64_t)tip->nTime);
     obj.pushKV("mediantime",            (int64_t)tip->GetMedianTimePast());
     obj.pushKV("verificationprogress",  GuessVerificationProgress(Params().TxData(), tip));
     obj.pushKV("initialblockdownload",  active_chainstate.IsInitialBlockDownload());

test/functional/rpc_blockchain.py

@@ -93,11 +93,14 @@ class BlockchainTest(BitcoinTestFramework):
             'pruned',
             'size_on_disk',
             'softforks',
+            'time',
             'verificationprogress',
             'warnings',
         ]
         res = self.nodes[0].getblockchaininfo()
 
+        assert isinstance(res['time'], int)
+
         # result should have these additional pruning keys if manual pruning is enabled
         assert_equal(sorted(res.keys()), sorted(['pruneheight', 'automatic_pruning'] + keys))