diff --git a/src/event-stream/core-node-message.ts b/src/event-stream/core-node-message.ts
index 8250fc265..066e0ffe6 100644
--- a/src/event-stream/core-node-message.ts
+++ b/src/event-stream/core-node-message.ts
@@ -326,7 +326,7 @@ export interface CoreNodeBlockMessage {
       missed_reward_slots: [];
     };
   };
-  block_time: number;
+  block_time: number | null;
   signer_bitvec?: string | null;
   signer_signature?: string[];
 }
diff --git a/src/event-stream/event-server.ts b/src/event-stream/event-server.ts
index 6d36ff7da..00b541eba 100644
--- a/src/event-stream/event-server.ts
+++ b/src/event-stream/event-server.ts
@@ -997,20 +997,20 @@ export function parseNewBlockMessage(
 ) {
   const counts = newCoreNoreBlockEventCounts();
 
+  // Nakamoto blocks now include their own `block_time`, but this will be empty for pre-Nakamoto
+  // blocks. We'll use the parent burn block timestamp as the receipt date for those. If both are
+  // blank, there's something wrong with Stacks core.
+  const block_time = msg.block_time ?? msg.burn_block_time;
+  if (block_time === undefined || block_time === null) {
+    throw new Error('Block message has no block_time or burn_block_time');
+  }
+
   const parsedTxs: CoreNodeParsedTxMessage[] = [];
   const blockData: CoreNodeMsgBlockData = {
     ...msg,
+    block_time,
   };
 
-  if (!blockData.block_time) {
-    // If running in IBD mode, we use the parent burn block timestamp as the receipt date,
-    // otherwise, use the current timestamp.
-    const stacksBlockReceiptDate = isEventReplay
-      ? msg.burn_block_time
-      : Math.round(Date.now() / 1000);
-    blockData.block_time = stacksBlockReceiptDate;
-  }
-
   msg.transactions.forEach(item => {
     const parsedTx = parseMessageTransaction(chainId, item, blockData, msg.events);
     if (parsedTx) {
diff --git a/tests/api/block-time.test.ts b/tests/api/block-time.test.ts
new file mode 100644
index 000000000..b4607b9a6
--- /dev/null
+++ b/tests/api/block-time.test.ts
@@ -0,0 +1,82 @@
+import { ChainID } from '@stacks/transactions';
+import { CoreNodeBlockMessage } from '../../src/event-stream/core-node-message';
+import { parseNewBlockMessage } from '../../src/event-stream/event-server';
+
+describe('block time tests', () => {
+  test('takes block_time from block header', () => {
+    const block: CoreNodeBlockMessage = {
+      block_time: 1716238792,
+      block_height: 1,
+      block_hash: '0x1234',
+      index_block_hash: '0x5678',
+      parent_index_block_hash: '0x9abc',
+      parent_block_hash: '0x1234',
+      parent_microblock: '0x1234',
+      parent_microblock_sequence: 0,
+      parent_burn_block_hash: '0x1234',
+      parent_burn_block_height: 0,
+      parent_burn_block_timestamp: 0,
+      burn_block_time: 1234567890,
+      burn_block_hash: '0x1234',
+      burn_block_height: 1,
+      miner_txid: '0x1234',
+      events: [],
+      transactions: [],
+      matured_miner_rewards: [],
+    };
+    const { dbData: parsed } = parseNewBlockMessage(ChainID.Mainnet, block, false);
+    expect(parsed.block.block_time).toEqual(1716238792); // Takes block_time from block header
+  });
+
+  test('takes burn_block_time from block header when block_time is not present', () => {
+    const block: CoreNodeBlockMessage = {
+      block_time: null,
+      block_height: 1,
+      block_hash: '0x1234',
+      index_block_hash: '0x5678',
+      parent_index_block_hash: '0x9abc',
+      parent_block_hash: '0x1234',
+      parent_microblock: '0x1234',
+      parent_microblock_sequence: 0,
+      parent_burn_block_hash: '0x1234',
+      parent_burn_block_height: 0,
+      parent_burn_block_timestamp: 0,
+      burn_block_time: 1234567890,
+      burn_block_hash: '0x1234',
+      burn_block_height: 1,
+      miner_txid: '0x1234',
+      events: [],
+      transactions: [],
+      matured_miner_rewards: [],
+    };
+    const { dbData: parsed } = parseNewBlockMessage(ChainID.Mainnet, block, false);
+    expect(parsed.block.block_time).toEqual(1234567890); // Takes burn_block_time from block header
+  });
+
+  test('throws error if block_time and burn_block_time are not present', () => {
+    // Use `any` to avoid type errors when setting `block_time` and `burn_block_time` to `null`.
+    const block: any = {
+      block_time: null,
+      burn_block_time: null,
+      block_height: 1,
+      block_hash: '0x1234',
+      index_block_hash: '0x5678',
+      parent_index_block_hash: '0x9abc',
+      parent_block_hash: '0x1234',
+      parent_microblock: '0x1234',
+      parent_microblock_sequence: 0,
+      parent_burn_block_hash: '0x1234',
+      parent_burn_block_height: 0,
+      parent_burn_block_timestamp: 0,
+      burn_block_hash: '0x1234',
+      burn_block_height: 1,
+      miner_txid: '0x1234',
+      events: [],
+      transactions: [],
+      matured_miner_rewards: [],
+    };
+    expect(() => parseNewBlockMessage(ChainID.Mainnet, block, false)).toThrow(
+      'Block message has no block_time or burn_block_time'
+    );
+  });
+});
diff --git a/tests/api/synthetic-stx-txs.test.ts b/tests/api/synthetic-stx-txs.test.ts
index 6d961f1da..b19769c30 100644
--- a/tests/api/synthetic-stx-txs.test.ts
+++ b/tests/api/synthetic-stx-txs.test.ts
@@ -3,7 +3,7 @@ import * as fs from 'fs';
 import * as path from 'path';
 import { DecodedTxResult, TxPayloadTypeID } from 'stacks-encoding-native-js';
 import { CoreNodeBlockMessage } from '../../src/event-stream/core-node-message';
-import { parseMessageTransaction } from '../../src/event-stream/reader';
+import { CoreNodeMsgBlockData, parseMessageTransaction } from '../../src/event-stream/reader';
 import { parseNewBlockMessage } from '../../src/event-stream/event-server';
 
 // Test processing of the psuedo-Stacks transactions, i.e. the ones that
@@ -20,7 +20,12 @@ describe('synthetic stx txs', () => {
     if (!txMsg) {
       throw new Error(`Cound not find tx ${txid}`);
     }
-    const parsed = parseMessageTransaction(ChainID.Mainnet, txMsg, blockMsg, blockMsg.events);
+    const parsed = parseMessageTransaction(
+      ChainID.Mainnet,
+      txMsg,
+      blockMsg as unknown as CoreNodeMsgBlockData,
+      blockMsg.events
+    );
     if (!parsed) {
       throw new Error(`Failed to parse ${txid}`);
     }
@@ -75,7 +80,12 @@ describe('synthetic stx txs', () => {
     if (!txMsg) {
       throw new Error(`Cound not find tx ${txid}`);
     }
-    const parsed = parseMessageTransaction(ChainID.Mainnet, txMsg, blockMsg, blockMsg.events);
+    const parsed = parseMessageTransaction(
+      ChainID.Mainnet,
+      txMsg,
+      blockMsg as unknown as CoreNodeMsgBlockData,
+      blockMsg.events
+    );
     if (!parsed) {
       throw new Error(`Failed to parse ${txid}`);
     }
@@ -130,7 +140,12 @@ describe('synthetic stx txs', () => {
     if (!txMsg) {
       throw new Error(`Cound not find tx ${txid}`);
     }
-    const parsed = parseMessageTransaction(ChainID.Mainnet, txMsg, blockMsg, blockMsg.events);
+    const parsed = parseMessageTransaction(
+      ChainID.Mainnet,
+      txMsg,
+      blockMsg as unknown as CoreNodeMsgBlockData,
+      blockMsg.events
+    );
     if (!parsed) {
       throw new Error(`Failed to parse ${txid}`);
     }
@@ -234,7 +249,12 @@ describe('synthetic stx txs', () => {
     if (!txMsg) {
       throw new Error(`Cound not find tx ${txid}`);
     }
-    const parsed = parseMessageTransaction(ChainID.Mainnet, txMsg, blockMsg, blockMsg.events);
+    const parsed = parseMessageTransaction(
+      ChainID.Mainnet,
+      txMsg,
+      blockMsg as unknown as CoreNodeMsgBlockData,
+      blockMsg.events
+    );
     if (!parsed) {
       throw new Error(`Failed to parse ${txid}`);
     }
@@ -333,7 +353,7 @@ describe('synthetic stx txs', () => {
       const parsed = parseMessageTransaction(
         ChainID.Mainnet,
         payload.txMsg,
-        payload.blockMsg,
+        payload.blockMsg as unknown as CoreNodeMsgBlockData,
         payload.blockMsg.events
       );
       let txType: 'contract_call' | 'token_transfer' | null;