Add two hour buffer to manual pruning

src/rpc/blockchain.cpp

@@ -820,7 +820,8 @@ UniValue pruneblockchain(const JSONRPCRequest& request)
         throw runtime_error(
             "pruneblockchain\n"
             "\nArguments:\n"
-            "1. \"height\"       (numeric, required) The block height to prune up to. May be set to a discrete height, or to a unix timestamp to prune based on block time.\n"
+            "1. \"height\"       (numeric, required) The block height to prune up to. May be set to a discrete height, or a unix timestamp\n"
+            "                  to prune blocks whose block time is at least 2 hours older than the provided timestamp.\n"
             "\nResult:\n"
             "n    (numeric) Height of the last block pruned.\n"
             "\nExamples:\n"
@@ -839,7 +840,8 @@ UniValue pruneblockchain(const JSONRPCRequest& request)
     // Height value more than a billion is too high to be a block height, and
     // too low to be a block time (corresponds to timestamp from Sep 2001).
     if (heightParam > 1000000000) {
-        CBlockIndex* pindex = chainActive.FindEarliestAtLeast(heightParam);
+        // Add a 2 hour buffer to include blocks which might have had old timestamps
+        CBlockIndex* pindex = chainActive.FindEarliestAtLeast(heightParam - 7200);
         if (!pindex) {
             throw JSONRPCError(RPC_INTERNAL_ERROR, "Could not find block with at least the specified timestamp.");
         }