diff --git a/XDCxlending/XDCxlending.go b/XDCxlending/XDCxlending.go
index d0093dc151..5922bddda1 100644
--- a/XDCxlending/XDCxlending.go
+++ b/XDCxlending/XDCxlending.go
@@ -280,7 +280,7 @@ func (l *Lending) SyncDataToSDKNode(chain consensus.ChainContext, statedb *state
 				updatedTakerLendingItem.AutoTopUp = false
 			case lendingstate.Repay:
 				updatedTakerLendingItem.Status = lendingstate.Repay
-				paymentBalance := lendingstate.CalculateTotalRepayValue(block.Time().Uint64(), tradeRecord.LiquidationTime, tradeRecord.Term, tradeRecord.Interest, tradeRecord.Amount)
+				paymentBalance := lendingstate.CalculateTotalRepayValue(block.Time(), tradeRecord.LiquidationTime, tradeRecord.Term, tradeRecord.Interest, tradeRecord.Amount)
 				updatedTakerLendingItem.Quantity = paymentBalance
 				updatedTakerLendingItem.FilledAmount = paymentBalance
 				// manual repay item
@@ -811,7 +811,7 @@ func (l *Lending) RollbackLendingData(txhash common.Hash) error {
 }
 
 func (l *Lending) ProcessLiquidationData(header *types.Header, chain consensus.ChainContext, statedb *state.StateDB, tradingState *tradingstate.TradingStateDB, lendingState *lendingstate.LendingStateDB) (updatedTrades map[common.Hash]*lendingstate.LendingTrade, liquidatedTrades, autoRepayTrades, autoTopUpTrades, autoRecallTrades []*lendingstate.LendingTrade, err error) {
-	time := header.Time
+	time := new(big.Int).SetUint64(header.Time)
 	updatedTrades = map[common.Hash]*lendingstate.LendingTrade{} // sum of liquidatedTrades, autoRepayTrades, autoTopUpTrades, autoRecallTrades
 	liquidatedTrades = []*lendingstate.LendingTrade{}
 	autoRepayTrades = []*lendingstate.LendingTrade{}
diff --git a/XDCxlending/order_processor.go b/XDCxlending/order_processor.go
index a46b9dafed..3914d5e9d2 100644
--- a/XDCxlending/order_processor.go
+++ b/XDCxlending/order_processor.go
@@ -347,7 +347,7 @@ func (l *Lending) processOrderList(header *types.Header, coinbase common.Address
 			log.Debug("Update quantity for orderId", "orderId", orderId.Hex())
 			log.Debug("LEND", "lendingOrderBook", lendingOrderBook.Hex(), "Taker Interest", Interest, "maker Interest", order.Interest, "Amount", tradedQuantity, "orderId", orderId, "side", side)
 			tradingId := lendingStateDB.GetTradeNonce(lendingOrderBook) + 1
-			liquidationTime := header.Time.Uint64() + order.Term
+			liquidationTime := header.Time + order.Term
 			liquidationPrice := new(big.Int).Mul(collateralPrice, liquidationRate)
 			liquidationPrice = new(big.Int).Div(liquidationPrice, depositRate)
 			lendingTrade := lendingstate.LendingTrade{
@@ -841,7 +841,7 @@ func (l *Lending) LiquidationExpiredTrade(header *types.Header, chain consensus.
 		_, liquidationRate, _ := lendingstate.GetCollateralDetail(statedb, lendingTrade.CollateralToken)
 		collateralAmount := new(big.Int).Mul(repayAmount, big.NewInt(100))
 		collateralAmount = new(big.Int).Div(collateralAmount, liquidationRate)
-		totalCollateralAmount := lendingstate.CalculateTotalRepayValue(header.Time.Uint64(), lendingTrade.LiquidationTime, lendingTrade.Term, lendingTrade.Interest, collateralAmount)
+		totalCollateralAmount := lendingstate.CalculateTotalRepayValue(header.Time, lendingTrade.LiquidationTime, lendingTrade.Term, lendingTrade.Interest, collateralAmount)
 		interestAmount := new(big.Int).Sub(totalCollateralAmount, collateralAmount)
 		repayAmount = new(big.Int).Add(repayAmount, interestAmount)
 	}
@@ -1159,7 +1159,7 @@ func (l *Lending) ProcessRepayLendingTrade(header *types.Header, chain consensus
 	if lendingTrade == lendingstate.EmptyLendingTrade {
 		return nil, fmt.Errorf("ProcessRepayLendingTrade for emptyLendingTrade is not allowed. lendingTradeId: %v", lendingTradeId)
 	}
-	time := header.Time.Uint64()
+	time := header.Time
 	tokenBalance := lendingstate.GetTokenBalance(lendingTrade.Borrower, lendingTrade.LendingToken, statedb)
 	paymentBalance := lendingstate.CalculateTotalRepayValue(time, lendingTrade.LiquidationTime, lendingTrade.Term, lendingTrade.Interest, lendingTrade.Amount)
 	log.Debug("ProcessRepay", "totalInterest", new(big.Int).Sub(paymentBalance, lendingTrade.Amount), "totalRepayValue", paymentBalance, "token", lendingTrade.LendingToken.Hex())
diff --git a/accounts/abi/bind/backends/simulated_test.go b/accounts/abi/bind/backends/simulated_test.go
index 62b72cbccc..ccdbc582a7 100644
--- a/accounts/abi/bind/backends/simulated_test.go
+++ b/accounts/abi/bind/backends/simulated_test.go
@@ -149,11 +149,11 @@ func TestAdjustTime(t *testing.T) {
 	)
 	defer sim.Close()
 
-	prevTime := sim.pendingBlock.Time().Uint64()
+	prevTime := sim.pendingBlock.Time()
 	if err := sim.AdjustTime(time.Second); err != nil {
 		t.Error(err)
 	}
-	newTime := sim.pendingBlock.Time().Uint64()
+	newTime := sim.pendingBlock.Time()
 
 	if newTime-prevTime != uint64(time.Second.Seconds()) {
 		t.Errorf("adjusted time not equal to a second. prev: %v, new: %v", prevTime, newTime)
@@ -182,11 +182,11 @@ func TestNewAdjustTimeFail(t *testing.T) {
 	}
 	sim.Commit()
 
-	prevTime := sim.pendingBlock.Time().Uint64()
+	prevTime := sim.pendingBlock.Time()
 	if err := sim.AdjustTime(time.Minute); err != nil {
 		t.Error(err)
 	}
-	newTime := sim.pendingBlock.Time().Uint64()
+	newTime := sim.pendingBlock.Time()
 	if newTime-prevTime != uint64(time.Minute.Seconds()) {
 		t.Errorf("adjusted time not equal to a minute. prev: %v, new: %v", prevTime, newTime)
 	}
@@ -198,7 +198,7 @@ func TestNewAdjustTimeFail(t *testing.T) {
 	}
 	sim.SendTransaction(context.Background(), signedTx2)
 	sim.Commit()
-	newTime = sim.pendingBlock.Time().Uint64()
+	newTime = sim.pendingBlock.Time()
 	if newTime-prevTime >= uint64(time.Minute.Seconds()) {
 		t.Errorf("time adjusted, but shouldn't be: prev: %v, new: %v", prevTime, newTime)
 	}
@@ -1385,7 +1385,7 @@ func TestForkResendTx(t *testing.T) {
 	if err != nil {
 		t.Fatalf("could not sign transaction: %v", err)
 	}
-	if err = sim.SendTransaction(context.Background(), tx);  err != nil {
+	if err = sim.SendTransaction(context.Background(), tx); err != nil {
 		t.Fatalf("sending transaction: %v", err)
 	}
 	sim.Commit()
diff --git a/consensus/XDPoS/api.go b/consensus/XDPoS/api.go
index 9f3dedf108..10f9e949eb 100644
--- a/consensus/XDPoS/api.go
+++ b/consensus/XDPoS/api.go
@@ -297,7 +297,7 @@ func (api *API) GetV2BlockByHeader(header *types.Header, uncle bool) *V2BlockInf
 		Round:      round,
 		Committed:  committed,
 		Miner:      header.Coinbase.Hash(),
-		Timestamp:  header.Time,
+		Timestamp:  new(big.Int).SetUint64(header.Time),
 		EncodedRLP: base64.StdEncoding.EncodeToString(encodeBytes),
 	}
 	return block
diff --git a/consensus/XDPoS/engines/engine_v1/engine.go b/consensus/XDPoS/engines/engine_v1/engine.go
index da8188e377..ee0b0b44e7 100644
--- a/consensus/XDPoS/engines/engine_v1/engine.go
+++ b/consensus/XDPoS/engines/engine_v1/engine.go
@@ -166,7 +166,7 @@ func (x *XDPoS_v1) verifyHeader(chain consensus.ChainReader, header *types.Heade
 			return consensus.ErrNoValidatorSignature
 		}
 		// Don't waste time checking blocks from the future
-		if header.Time.Cmp(big.NewInt(time.Now().Unix())) > 0 {
+		if header.Time > uint64(time.Now().Unix()) {
 			return consensus.ErrFutureBlock
 		}
 	}
@@ -230,7 +230,7 @@ func (x *XDPoS_v1) verifyCascadingFields(chain consensus.ChainReader, header *ty
 	if parent == nil || parent.Number.Uint64() != number-1 || parent.Hash() != header.ParentHash {
 		return consensus.ErrUnknownAncestor
 	}
-	if parent.Time.Uint64()+x.config.Period > header.Time.Uint64() {
+	if parent.Time+x.config.Period > header.Time {
 		return utils.ErrInvalidTimestamp
 	}
 	// Verify the header's EIP-1559 attributes.
@@ -423,7 +423,7 @@ func (x *XDPoS_v1) YourTurn(chain consensus.ChainReader, parent *types.Header, s
 			gap = minePeriodCheckpoint * int64(h)
 		}
 		log.Info("Distance from the parent block", "seconds", gap, "hops", h)
-		waitedTime := time.Now().Unix() - parent.Time.Int64()
+		waitedTime := time.Now().Unix() - int64(parent.Time)
 		if gap > waitedTime {
 			return false, nil
 		}
@@ -775,9 +775,9 @@ func (x *XDPoS_v1) Prepare(chain consensus.ChainReader, header *types.Header) er
 
 	// Ensure the timestamp has the correct delay
 
-	header.Time = new(big.Int).Add(parent.Time, new(big.Int).SetUint64(x.config.Period))
-	if header.Time.Int64() < time.Now().Unix() {
-		header.Time = big.NewInt(time.Now().Unix())
+	header.Time = parent.Time + x.config.Period
+	if timeNow := uint64(time.Now().Unix()); header.Time < timeNow {
+		header.Time = timeNow
 	}
 	return nil
 }
diff --git a/consensus/XDPoS/engines/engine_v2/engine.go b/consensus/XDPoS/engines/engine_v2/engine.go
index 98c29d92f4..9de918d1dc 100644
--- a/consensus/XDPoS/engines/engine_v2/engine.go
+++ b/consensus/XDPoS/engines/engine_v2/engine.go
@@ -283,7 +283,7 @@ func (x *XDPoS_v2) YourTurn(chain consensus.ChainReader, parent *types.Header, s
 		}
 	}
 
-	waitedTime := time.Now().Unix() - parent.Time.Int64()
+	waitedTime := time.Now().Unix() - int64(parent.Time)
 	minePeriod := x.config.V2.Config(uint64(x.currentRound)).MinePeriod
 	if waitedTime < int64(minePeriod) {
 		log.Trace("[YourTurn] wait after mine period", "minePeriod", minePeriod, "waitedTime", waitedTime)
@@ -374,9 +374,9 @@ func (x *XDPoS_v2) Prepare(chain consensus.ChainReader, header *types.Header) er
 	// Ensure the timestamp has the correct delay
 	// TODO: Proper deal with time
 	// TODO: if timestamp > current time, how to deal with future timestamp
-	header.Time = new(big.Int).Add(parent.Time, new(big.Int).SetUint64(x.config.Period))
-	if header.Time.Int64() < time.Now().Unix() {
-		header.Time = big.NewInt(time.Now().Unix())
+	header.Time = parent.Time + x.config.Period
+	if timeNow := uint64(time.Now().Unix()); header.Time < timeNow {
+		header.Time = timeNow
 	}
 
 	if header.Coinbase != signer {
diff --git a/consensus/XDPoS/engines/engine_v2/verifyHeader.go b/consensus/XDPoS/engines/engine_v2/verifyHeader.go
index cef1331f67..41ebf4f56f 100644
--- a/consensus/XDPoS/engines/engine_v2/verifyHeader.go
+++ b/consensus/XDPoS/engines/engine_v2/verifyHeader.go
@@ -43,7 +43,7 @@ func (x *XDPoS_v2) verifyHeader(chain consensus.ChainReader, header *types.Heade
 
 	if fullVerify {
 		// Don't waste time checking blocks from the future
-		if header.Time.Int64() > time.Now().Unix() {
+		if header.Time > uint64(time.Now().Unix()) {
 			return consensus.ErrFutureBlock
 		}
 	}
@@ -69,8 +69,8 @@ func (x *XDPoS_v2) verifyHeader(chain consensus.ChainReader, header *types.Heade
 	}
 
 	minePeriod := uint64(x.config.V2.Config(uint64(round)).MinePeriod)
-	if parent.Number.Uint64() > x.config.V2.SwitchBlock.Uint64() && parent.Time.Uint64()+minePeriod > header.Time.Uint64() {
-		log.Warn("[verifyHeader] Fail to verify header due to invalid timestamp", "ParentTime", parent.Time.Uint64(), "MinePeriod", minePeriod, "HeaderTime", header.Time.Uint64(), "Hash", header.Hash().Hex())
+	if parent.Number.Uint64() > x.config.V2.SwitchBlock.Uint64() && parent.Time+minePeriod > header.Time {
+		log.Warn("[verifyHeader] Fail to verify header due to invalid timestamp", "ParentTime", parent.Time, "MinePeriod", minePeriod, "HeaderTime", header.Time, "Hash", header.Hash().Hex())
 		return utils.ErrInvalidTimestamp
 	}
 
diff --git a/consensus/clique/clique.go b/consensus/clique/clique.go
index 6187028711..df2b724293 100644
--- a/consensus/clique/clique.go
+++ b/consensus/clique/clique.go
@@ -275,7 +275,7 @@ func (c *Clique) verifyHeader(chain consensus.ChainReader, header *types.Header,
 	number := header.Number.Uint64()
 
 	// Don't waste time checking blocks from the future
-	if header.Time.Cmp(big.NewInt(time.Now().Unix())) > 0 {
+	if header.Time > uint64(time.Now().Unix()) {
 		return consensus.ErrFutureBlock
 	}
 	// Checkpoint blocks need to enforce zero beneficiary
@@ -353,7 +353,7 @@ func (c *Clique) verifyCascadingFields(chain consensus.ChainReader, header *type
 	if parent == nil || parent.Number.Uint64() != number-1 || parent.Hash() != header.ParentHash {
 		return consensus.ErrUnknownAncestor
 	}
-	if parent.Time.Uint64()+c.config.Period > header.Time.Uint64() {
+	if parent.Time+c.config.Period > header.Time {
 		return ErrInvalidTimestamp
 	}
 	// Verify that the gas limit remains within allowed bounds
@@ -574,9 +574,9 @@ func (c *Clique) Prepare(chain consensus.ChainReader, header *types.Header) erro
 	if parent == nil {
 		return consensus.ErrUnknownAncestor
 	}
-	header.Time = new(big.Int).Add(parent.Time, new(big.Int).SetUint64(c.config.Period))
-	if header.Time.Int64() < time.Now().Unix() {
-		header.Time = big.NewInt(time.Now().Unix())
+	header.Time = parent.Time + c.config.Period
+	if header.Time < uint64(time.Now().Unix()) {
+		header.Time = uint64(time.Now().Unix())
 	}
 	return nil
 }
@@ -642,7 +642,7 @@ func (c *Clique) Seal(chain consensus.ChainReader, block *types.Block, stop <-ch
 		}
 	}
 	// Sweet, the protocol permits us to sign the block, wait for our time
-	delay := time.Until(time.Unix(header.Time.Int64(), 0))
+	delay := time.Until(time.Unix(int64(header.Time), 0))
 	if header.Difficulty.Cmp(diffNoTurn) == 0 {
 		// It's not our turn explicitly to sign, delay it a bit
 		wiggle := time.Duration(len(snap.Signers)/2+1) * wiggleTime
diff --git a/consensus/ethash/algorithm_test.go b/consensus/ethash/algorithm_test.go
index 40524a81e4..ec8405fa35 100644
--- a/consensus/ethash/algorithm_test.go
+++ b/consensus/ethash/algorithm_test.go
@@ -707,7 +707,7 @@ func TestConcurrentDiskCacheGeneration(t *testing.T) {
 		Difficulty:  big.NewInt(167925187834220),
 		GasLimit:    4015682,
 		GasUsed:     0,
-		Time:        big.NewInt(1488928920),
+		Time:        1488928920,
 		Extra:       []byte("www.bw.com"),
 		MixDigest:   common.HexToHash("0x3e140b0784516af5e5ec6730f2fb20cca22f32be399b9e4ad77d32541f798cd0"),
 		Nonce:       types.EncodeNonce(0xf400cd0006070c49),
diff --git a/consensus/ethash/consensus.go b/consensus/ethash/consensus.go
index 2bcfd6e0b6..0008100503 100644
--- a/consensus/ethash/consensus.go
+++ b/consensus/ethash/consensus.go
@@ -25,7 +25,6 @@ import (
 	"time"
 
 	"github.com/XinFinOrg/XDPoSChain/common"
-	"github.com/XinFinOrg/XDPoSChain/common/math"
 	"github.com/XinFinOrg/XDPoSChain/consensus"
 	"github.com/XinFinOrg/XDPoSChain/consensus/misc"
 	"github.com/XinFinOrg/XDPoSChain/consensus/misc/eip1559"
@@ -38,10 +37,10 @@ import (
 
 // Ethash proof-of-work protocol constants.
 var (
-	FrontierBlockReward    *big.Int = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
-	ByzantiumBlockReward   *big.Int = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Byzantium
-	maxUncles                       = 2                 // Maximum number of uncles allowed in a single block
-	allowedFutureBlockTime          = 15 * time.Second  // Max time from current time allowed for blocks, before they're considered future blocks
+	FrontierBlockReward           *big.Int = big.NewInt(5e+18) // Block reward in wei for successfully mining a block
+	ByzantiumBlockReward          *big.Int = big.NewInt(3e+18) // Block reward in wei for successfully mining a block upward from Byzantium
+	maxUncles                              = 2                 // Maximum number of uncles allowed in a single block
+	allowedFutureBlockTimeSeconds          = int64(15)         // Max seconds from current time allowed for blocks, before they're considered future blocks
 )
 
 // Various error messages to mark blocks invalid. These should be private to
@@ -49,7 +48,6 @@ var (
 // codebase, inherently breaking if the engine is swapped out. Please put common
 // error types into the consensus package.
 var (
-	errLargeBlockTime    = errors.New("timestamp too big")
 	errZeroBlockTime     = errors.New("timestamp equals parent's")
 	errTooManyUncles     = errors.New("too many uncles")
 	errDuplicateUncle    = errors.New("duplicate uncle")
@@ -228,20 +226,16 @@ func (ethash *Ethash) verifyHeader(chain consensus.ChainReader, header, parent *
 		return fmt.Errorf("extra-data too long: %d > %d", len(header.Extra), params.MaximumExtraDataSize)
 	}
 	// Verify the header's timestamp
-	if uncle {
-		if header.Time.Cmp(math.MaxBig256) > 0 {
-			return errLargeBlockTime
-		}
-	} else {
-		if header.Time.Cmp(big.NewInt(time.Now().Add(allowedFutureBlockTime).Unix())) > 0 {
+	if !uncle {
+		if header.Time > uint64(time.Now().Unix()+allowedFutureBlockTimeSeconds) {
 			return consensus.ErrFutureBlock
 		}
 	}
-	if header.Time.Cmp(parent.Time) <= 0 {
+	if header.Time <= parent.Time {
 		return errZeroBlockTime
 	}
 	// Verify the block's difficulty based in it's timestamp and parent's difficulty
-	expected := ethash.CalcDifficulty(chain, header.Time.Uint64(), parent)
+	expected := ethash.CalcDifficulty(chain, header.Time, parent)
 
 	if expected.Cmp(header.Difficulty) != 0 {
 		return fmt.Errorf("invalid difficulty: have %v, want %v", header.Difficulty, expected)
@@ -331,7 +325,7 @@ func calcDifficultyByzantium(time uint64, parent *types.Header) *big.Int {
 	//        ) + 2^(periodCount - 2)
 
 	bigTime := new(big.Int).SetUint64(time)
-	bigParentTime := new(big.Int).Set(parent.Time)
+	bigParentTime := new(big.Int).SetUint64(parent.Time)
 
 	// holds intermediate values to make the algo easier to read & audit
 	x := new(big.Int)
@@ -390,7 +384,7 @@ func calcDifficultyHomestead(time uint64, parent *types.Header) *big.Int {
 	//        ) + 2^(periodCount - 2)
 
 	bigTime := new(big.Int).SetUint64(time)
-	bigParentTime := new(big.Int).Set(parent.Time)
+	bigParentTime := new(big.Int).SetUint64(parent.Time)
 
 	// holds intermediate values to make the algo easier to read & audit
 	x := new(big.Int)
@@ -438,7 +432,7 @@ func calcDifficultyFrontier(time uint64, parent *types.Header) *big.Int {
 	bigParentTime := new(big.Int)
 
 	bigTime.SetUint64(time)
-	bigParentTime.Set(parent.Time)
+	bigParentTime.SetUint64(parent.Time)
 
 	if bigTime.Sub(bigTime, bigParentTime).Cmp(params.DurationLimit) < 0 {
 		diff.Add(parent.Difficulty, adjust)
@@ -512,7 +506,7 @@ func (ethash *Ethash) Prepare(chain consensus.ChainReader, header *types.Header)
 	if parent == nil {
 		return consensus.ErrUnknownAncestor
 	}
-	header.Difficulty = ethash.CalcDifficulty(chain, header.Time.Uint64(), parent)
+	header.Difficulty = ethash.CalcDifficulty(chain, header.Time, parent)
 	return nil
 }
 
diff --git a/consensus/ethash/consensus_test.go b/consensus/ethash/consensus_test.go
index 3d56792cdd..fe0647e521 100644
--- a/consensus/ethash/consensus_test.go
+++ b/consensus/ethash/consensus_test.go
@@ -76,7 +76,7 @@ func TestCalcDifficulty(t *testing.T) {
 		number := new(big.Int).Sub(test.CurrentBlocknumber, big.NewInt(1))
 		diff := CalcDifficulty(config, test.CurrentTimestamp, &types.Header{
 			Number:     number,
-			Time:       new(big.Int).SetUint64(test.ParentTimestamp),
+			Time:       test.ParentTimestamp,
 			Difficulty: test.ParentDifficulty,
 		})
 		if diff.Cmp(test.CurrentDifficulty) != 0 {
diff --git a/consensus/tests/engine_v1_tests/helper.go b/consensus/tests/engine_v1_tests/helper.go
index cbebfd1bbf..7da93279e2 100644
--- a/consensus/tests/engine_v1_tests/helper.go
+++ b/consensus/tests/engine_v1_tests/helper.go
@@ -354,7 +354,7 @@ func createBlockFromHeader(bc *core.BlockChain, customHeader *types.Header, txs
 		Difficulty:  difficulty,
 		Number:      customHeader.Number,
 		GasLimit:    1200000000,
-		Time:        big.NewInt(time.Now().Unix()),
+		Time:        uint64(time.Now().Unix()),
 		Extra:       customHeader.Extra,
 		Validator:   customHeader.Validator,
 		Validators:  customHeader.Validators,
diff --git a/consensus/tests/engine_v2_tests/authorised_masternode_test.go b/consensus/tests/engine_v2_tests/authorised_masternode_test.go
index 8f39886ec6..e67651515f 100644
--- a/consensus/tests/engine_v2_tests/authorised_masternode_test.go
+++ b/consensus/tests/engine_v2_tests/authorised_masternode_test.go
@@ -1,7 +1,6 @@
 package engine_v2_tests
 
 import (
-	"math/big"
 	"testing"
 	"time"
 
@@ -41,7 +40,7 @@ func TestIsYourTurnConsensusV2(t *testing.T) {
 	blockCoinBase := "0x111000000000000000000000000000000123"
 	currentBlock = CreateBlock(blockchain, params.TestXDPoSMockChainConfig, currentBlock, blockNum, 1, blockCoinBase, signer, signFn, nil, nil, "")
 	currentBlockHeader := currentBlock.Header()
-	currentBlockHeader.Time = big.NewInt(time.Now().Unix())
+	currentBlockHeader.Time = uint64(time.Now().Unix())
 	err := blockchain.InsertBlock(currentBlock)
 	assert.Nil(t, err)
 	adaptor.Initial(blockchain, currentBlockHeader)
@@ -94,7 +93,7 @@ func TestIsYourTurnConsensusV2CrossConfig(t *testing.T) {
 	blockCoinBase := "0x111000000000000000000000000000000123"
 	currentBlock = CreateBlock(blockchain, params.TestXDPoSMockChainConfig, currentBlock, blockNum, 10, blockCoinBase, signer, signFn, nil, nil, "")
 	currentBlockHeader := currentBlock.Header()
-	currentBlockHeader.Time = big.NewInt(time.Now().Unix())
+	currentBlockHeader.Time = uint64(time.Now().Unix())
 	err := blockchain.InsertBlock(currentBlock)
 	adaptor.EngineV2.SetNewRoundFaker(blockchain, types.Round(10), false)
 	assert.Nil(t, err)
diff --git a/consensus/tests/engine_v2_tests/helper.go b/consensus/tests/engine_v2_tests/helper.go
index 4586502ceb..ccecf8e997 100644
--- a/consensus/tests/engine_v2_tests/helper.go
+++ b/consensus/tests/engine_v2_tests/helper.go
@@ -877,7 +877,7 @@ func createBlockFromHeader(bc *core.BlockChain, customHeader *types.Header, txs
 		Difficulty:  difficulty,
 		Number:      customHeader.Number,
 		GasLimit:    1200000000,
-		Time:        big.NewInt(time.Now().Unix() - 1000000 + int64(customHeader.Number.Uint64()*10)),
+		Time:        uint64(time.Now().Unix() - 1000000 + int64(customHeader.Number.Uint64()*10)),
 		Extra:       customHeader.Extra,
 		Validator:   customHeader.Validator,
 		Validators:  customHeader.Validators,
diff --git a/consensus/tests/engine_v2_tests/mine_test.go b/consensus/tests/engine_v2_tests/mine_test.go
index 7a66536eaf..6ae82986e2 100644
--- a/consensus/tests/engine_v2_tests/mine_test.go
+++ b/consensus/tests/engine_v2_tests/mine_test.go
@@ -145,13 +145,13 @@ func TestPrepareFail(t *testing.T) {
 	blockchain, _, currentBlock, signer, _, _ := PrepareXDCTestBlockChainForV2Engine(t, int(config.XDPoS.Epoch), config, nil)
 	adaptor := blockchain.Engine().(*XDPoS.XDPoS)
 
-	tstamp := time.Now().Unix()
+	tstamp := uint64(time.Now().Unix())
 
 	notReadyToProposeHeader := &types.Header{
 		ParentHash: currentBlock.Hash(),
 		Number:     big.NewInt(int64(901)),
 		GasLimit:   params.TargetGasLimit,
-		Time:       big.NewInt(tstamp),
+		Time:       tstamp,
 		Coinbase:   signer,
 	}
 
@@ -162,7 +162,7 @@ func TestPrepareFail(t *testing.T) {
 		ParentHash: currentBlock.Hash(),
 		Number:     big.NewInt(int64(901)),
 		GasLimit:   params.TargetGasLimit,
-		Time:       big.NewInt(tstamp),
+		Time:       tstamp,
 		Coinbase:   signer,
 	}
 	// trigger initial which will set the highestQC
@@ -176,7 +176,7 @@ func TestPrepareFail(t *testing.T) {
 		ParentHash: currentBlock.Hash(),
 		Number:     big.NewInt(int64(901)),
 		GasLimit:   params.TargetGasLimit,
-		Time:       big.NewInt(tstamp),
+		Time:       tstamp,
 	}
 
 	err = adaptor.Prepare(blockchain, header901WithoutCoinbase)
@@ -191,13 +191,13 @@ func TestPrepareHappyPath(t *testing.T) {
 	_, err := adaptor.YourTurn(blockchain, currentBlock.Header(), signer)
 	assert.Nil(t, err)
 
-	tstamp := time.Now().Unix()
+	tstamp := uint64(time.Now().Unix())
 
 	header901 := &types.Header{
 		ParentHash: currentBlock.Hash(),
 		Number:     big.NewInt(int64(901)),
 		GasLimit:   params.TargetGasLimit,
-		Time:       big.NewInt(tstamp),
+		Time:       tstamp,
 		Coinbase:   signer,
 	}
 
@@ -271,13 +271,13 @@ func TestUpdateMultipleMasterNodes(t *testing.T) {
 		}
 	}
 
-	tstamp := time.Now().Unix()
+	tstamp := uint64(time.Now().Unix())
 
 	header1800 := &types.Header{
 		ParentHash: parentBlock.Hash(),
 		Number:     big.NewInt(int64(1800)),
 		GasLimit:   params.TargetGasLimit,
-		Time:       big.NewInt(tstamp),
+		Time:       tstamp,
 		Coinbase:   voterAddr,
 	}
 
diff --git a/consensus/tests/engine_v2_tests/timeout_test.go b/consensus/tests/engine_v2_tests/timeout_test.go
index 8ce3edbc91..a990e77df5 100644
--- a/consensus/tests/engine_v2_tests/timeout_test.go
+++ b/consensus/tests/engine_v2_tests/timeout_test.go
@@ -1,7 +1,6 @@
 package engine_v2_tests
 
 import (
-	"math/big"
 	"strconv"
 	"strings"
 	"testing"
@@ -111,7 +110,7 @@ func TestTimeoutPeriodAndThreadholdConfigChange(t *testing.T) {
 	blockCoinBase := "0x111000000000000000000000000000000123"
 	currentBlock = CreateBlock(blockchain, params.TestXDPoSMockChainConfig, currentBlock, blockNum, 900, blockCoinBase, signer, signFn, nil, nil, "")
 	currentBlockHeader := currentBlock.Header()
-	currentBlockHeader.Time = big.NewInt(time.Now().Unix())
+	currentBlockHeader.Time = uint64(time.Now().Unix())
 	err := blockchain.InsertBlock(currentBlock)
 	assert.Nil(t, err)
 
diff --git a/consensus/tests/engine_v2_tests/verify_header_test.go b/consensus/tests/engine_v2_tests/verify_header_test.go
index 1237c49914..844a0ec645 100644
--- a/consensus/tests/engine_v2_tests/verify_header_test.go
+++ b/consensus/tests/engine_v2_tests/verify_header_test.go
@@ -53,7 +53,7 @@ func TestShouldVerifyBlock(t *testing.T) {
 	assert.Equal(t, consensus.ErrNoValidatorSignatureV2, err)
 
 	blockFromFuture := blockchain.GetBlockByNumber(902).Header()
-	blockFromFuture.Time = big.NewInt(time.Now().Unix() + 10000)
+	blockFromFuture.Time = uint64(time.Now().Unix() + 10000)
 	err = adaptor.VerifyHeader(blockchain, blockFromFuture, true)
 	assert.Equal(t, consensus.ErrFutureBlock, err)
 
@@ -97,7 +97,7 @@ func TestShouldVerifyBlock(t *testing.T) {
 
 	block901 := blockchain.GetBlockByNumber(901).Header()
 	tooFastMinedBlock := blockchain.GetBlockByNumber(902).Header()
-	tooFastMinedBlock.Time = big.NewInt(block901.Time.Int64() - 10)
+	tooFastMinedBlock.Time = block901.Time - 10
 	err = adaptor.VerifyHeader(blockchain, tooFastMinedBlock, true)
 	assert.Equal(t, utils.ErrInvalidTimestamp, err)
 
@@ -351,7 +351,7 @@ func TestConfigSwitchOnDifferentMindPeriod(t *testing.T) {
 	// after 910 require 5 signs, but we only give 3 signs
 	block911 := blockchain.GetBlockByNumber(911).Header()
 	block911.Extra = extraInBytes
-	block911.Time = big.NewInt(blockchain.GetBlockByNumber(910).Time().Int64() + 2) //2 is previous config, should get the right config from round
+	block911.Time = blockchain.GetBlockByNumber(910).Time() + 2 // 2 is previous config, should get the right config from round
 	err = adaptor.VerifyHeader(blockchain, block911, true)
 
 	assert.Equal(t, utils.ErrInvalidTimestamp, err)
diff --git a/core/blockchain.go b/core/blockchain.go
index 675278d05a..50d82d02da 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -429,9 +429,9 @@ func (bc *BlockChain) loadLastState() error {
 	blockTd := bc.GetTd(currentBlock.Hash(), currentBlock.NumberU64())
 	fastTd := bc.GetTd(currentFastBlock.Hash(), currentFastBlock.NumberU64())
 
-	log.Info("Loaded most recent local header", "number", currentHeader.Number, "hash", currentHeader.Hash(), "td", headerTd, "age", common.PrettyAge(time.Unix(currentHeader.Time.Int64(), 0)))
-	log.Info("Loaded most recent local full block", "number", currentBlock.Number(), "hash", currentBlock.Hash(), "td", blockTd, "age", common.PrettyAge(time.Unix(currentBlock.Time().Int64(), 0)))
-	log.Info("Loaded most recent local fast block", "number", currentFastBlock.Number(), "hash", currentFastBlock.Hash(), "td", fastTd, "age", common.PrettyAge(time.Unix(currentFastBlock.Time().Int64(), 0)))
+	log.Info("Loaded most recent local header", "number", currentHeader.Number, "hash", currentHeader.Hash(), "td", headerTd, "age", common.PrettyAge(time.Unix(int64(currentHeader.Time), 0)))
+	log.Info("Loaded most recent local full block", "number", currentBlock.Number(), "hash", currentBlock.Hash(), "td", blockTd, "age", common.PrettyAge(time.Unix(int64(currentBlock.Time()), 0)))
+	log.Info("Loaded most recent local fast block", "number", currentFastBlock.Number(), "hash", currentFastBlock.Hash(), "td", fastTd, "age", common.PrettyAge(time.Unix(int64(currentFastBlock.Time()), 0)))
 
 	return nil
 }
@@ -1309,7 +1309,7 @@ func (bc *BlockChain) InsertReceiptChain(blockChain types.Blocks, receiptChain [
 
 	context := []interface{}{
 		"count", stats.processed, "elapsed", common.PrettyDuration(time.Since(start)),
-		"number", head.Number(), "hash", head.Hash(), "age", common.PrettyAge(time.Unix(head.Time().Int64(), 0)),
+		"number", head.Number(), "hash", head.Hash(), "age", common.PrettyAge(time.Unix(int64(head.Time()), 0)),
 		"size", common.StorageSize(bytes),
 	}
 	if stats.ignored > 0 {
@@ -1570,8 +1570,8 @@ func (bc *BlockChain) writeBlockWithState(block *types.Block, receipts []*types.
 // accepted for future processing, and returns an error if the block is too far
 // ahead and was not added.
 func (bc *BlockChain) addFutureBlock(block *types.Block) error {
-	max := big.NewInt(time.Now().Unix() + maxTimeFutureBlocks)
-	if block.Time().Cmp(max) > 0 {
+	max := uint64(time.Now().Unix()) + maxTimeFutureBlocks
+	if block.Time() > max {
 		return fmt.Errorf("future block timestamp %v > allowed %v", block.Time(), max)
 	}
 	bc.futureBlocks.Add(block.Hash(), block)
@@ -2792,7 +2792,7 @@ func (bc *BlockChain) logExchangeData(block *types.Block) {
 				rejectedOrders = rejected.([]*tradingstate.OrderItem)
 			}
 
-			txMatchTime := time.Unix(block.Header().Time.Int64(), 0).UTC()
+			txMatchTime := time.Unix(int64(block.Header().Time), 0).UTC()
 			if err := XDCXService.SyncDataToSDKNode(takerOrderInTx, txMatchBatch.TxHash, txMatchTime, currentState, trades, rejectedOrders, &dirtyOrderCount); err != nil {
 				log.Crit("failed to SyncDataToSDKNode ", "blockNumber", block.Number(), "err", err)
 				return
@@ -2846,7 +2846,7 @@ func (bc *BlockChain) logLendingData(block *types.Block) {
 				rejectedOrders = rejected.([]*lendingstate.LendingItem)
 			}
 
-			txMatchTime := time.Unix(block.Header().Time.Int64(), 0).UTC()
+			txMatchTime := time.Unix(int64(block.Header().Time), 0).UTC()
 			statedb, _ := bc.State()
 
 			if err := lendingService.SyncDataToSDKNode(bc, statedb.Copy(), block, item, batch.TxHash, txMatchTime, trades, rejectedOrders, &dirtyOrderCount); err != nil {
@@ -2867,7 +2867,7 @@ func (bc *BlockChain) logLendingData(block *types.Block) {
 			finalizedTrades = finalizedData.(map[common.Hash]*lendingstate.LendingTrade)
 		}
 		if len(finalizedTrades) > 0 {
-			if err := lendingService.UpdateLiquidatedTrade(block.Time().Uint64(), finalizedTx, finalizedTrades); err != nil {
+			if err := lendingService.UpdateLiquidatedTrade(block.Time(), finalizedTx, finalizedTrades); err != nil {
 				log.Crit("lending: failed to UpdateLiquidatedTrade ", "blockNumber", block.Number(), "err", err)
 			}
 		}
diff --git a/core/blockchain_insert.go b/core/blockchain_insert.go
index a80925ab73..b376b98363 100644
--- a/core/blockchain_insert.go
+++ b/core/blockchain_insert.go
@@ -60,7 +60,7 @@ func (st *insertStats) report(chain []*types.Block, index int, cache common.Stor
 			"elapsed", common.PrettyDuration(elapsed), "mgasps", float64(st.usedGas) * 1000 / float64(elapsed),
 			"number", end.Number(), "hash", end.Hash(),
 		}
-		if timestamp := time.Unix(end.Time().Int64(), 0); time.Since(timestamp) > time.Minute {
+		if timestamp := time.Unix(int64(end.Time()), 0); time.Since(timestamp) > time.Minute {
 			context = append(context, []interface{}{"age", common.PrettyAge(timestamp)}...)
 		}
 		context = append(context, []interface{}{"dirty", cache}...)
diff --git a/core/chain_makers.go b/core/chain_makers.go
index 5e2fcfcfea..39979664cb 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -189,12 +189,12 @@ func (b *BlockGen) PrevBlock(index int) *types.Block {
 // associated difficulty. It's useful to test scenarios where forking is not
 // tied to chain length directly.
 func (b *BlockGen) OffsetTime(seconds int64) {
-	b.header.Time.Add(b.header.Time, new(big.Int).SetInt64(seconds))
-	if b.header.Time.Cmp(b.parent.Header().Time) <= 0 {
+	b.header.Time += uint64(seconds)
+	if b.header.Time <= b.parent.Header().Time {
 		panic("block time out of range")
 	}
 	chainReader := &fakeChainReader{config: b.config}
-	b.header.Difficulty = b.engine.CalcDifficulty(chainReader, b.header.Time.Uint64(), b.parent.Header())
+	b.header.Difficulty = b.engine.CalcDifficulty(chainReader, b.header.Time, b.parent.Header())
 }
 
 // GenerateChain creates a chain of n blocks. The first block's
@@ -277,20 +277,19 @@ func GenerateChainWithGenesis(genesis *Genesis, engine consensus.Engine, n int,
 }
 
 func makeHeader(chain consensus.ChainReader, parent *types.Block, state *state.StateDB, engine consensus.Engine) *types.Header {
-	var time *big.Int
-	if parent.Time() == nil {
-		time = big.NewInt(10)
+	var time uint64
+	if parent.Time() == 0 {
+		time = 10
 	} else {
-		time = new(big.Int).Add(parent.Time(), big.NewInt(10)) // block time is fixed at 10 seconds
+		time = parent.Time() + 10 // block time is fixed at 10 seconds
 	}
-
 	header := &types.Header{
 		Root:       state.IntermediateRoot(chain.Config().IsEIP158(parent.Number())),
 		ParentHash: parent.Hash(),
 		Coinbase:   parent.Coinbase(),
-		Difficulty: engine.CalcDifficulty(chain, time.Uint64(), &types.Header{
+		Difficulty: engine.CalcDifficulty(chain, time, &types.Header{
 			Number:     parent.Number(),
-			Time:       new(big.Int).Sub(time, big.NewInt(10)),
+			Time:       time - 10,
 			Difficulty: parent.Difficulty(),
 			UncleHash:  parent.UncleHash(),
 		}),
diff --git a/core/evm.go b/core/evm.go
index 4f42850fee..bbf6249cd5 100644
--- a/core/evm.go
+++ b/core/evm.go
@@ -60,7 +60,7 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 		GetHash:     GetHashFn(header, chain),
 		Coinbase:    beneficiary,
 		BlockNumber: new(big.Int).Set(header.Number),
-		Time:        new(big.Int).Set(header.Time),
+		Time:        new(big.Int).SetUint64(header.Time),
 		Difficulty:  new(big.Int).Set(header.Difficulty),
 		BaseFee:     baseFee,
 		GasLimit:    header.GasLimit,
diff --git a/core/genesis.go b/core/genesis.go
index 75e019bfd6..77cb447180 100644
--- a/core/genesis.go
+++ b/core/genesis.go
@@ -197,7 +197,7 @@ func (g *Genesis) ToBlock(db ethdb.Database) *types.Block {
 	head := &types.Header{
 		Number:     new(big.Int).SetUint64(g.Number),
 		Nonce:      types.EncodeNonce(g.Nonce),
-		Time:       new(big.Int).SetUint64(g.Timestamp),
+		Time:       g.Timestamp,
 		ParentHash: g.ParentHash,
 		Extra:      g.ExtraData,
 		GasLimit:   g.GasLimit,
diff --git a/core/headerchain.go b/core/headerchain.go
index 28b7ec5358..ea1123e59d 100644
--- a/core/headerchain.go
+++ b/core/headerchain.go
@@ -304,7 +304,7 @@ func (hc *HeaderChain) InsertHeaderChain(chain []*types.Header, writeHeader WhCa
 		"count", stats.processed, "elapsed", common.PrettyDuration(time.Since(start)),
 		"number", last.Number, "hash", last.Hash(),
 	}
-	if timestamp := time.Unix(last.Time.Int64(), 0); time.Since(timestamp) > time.Minute {
+	if timestamp := time.Unix(int64(last.Time), 0); time.Since(timestamp) > time.Minute {
 		context = append(context, []interface{}{"age", common.PrettyAge(timestamp)}...)
 	}
 	if stats.ignored > 0 {
diff --git a/core/state_processor_test.go b/core/state_processor_test.go
index 830e2badc6..999ab04d9c 100644
--- a/core/state_processor_test.go
+++ b/core/state_processor_test.go
@@ -256,7 +256,7 @@ func GenerateBadBlock(t *testing.T, parent *types.Block, engine consensus.Engine
 	header := &types.Header{
 		ParentHash: parent.Hash(),
 		Coinbase:   parent.Coinbase(),
-		Difficulty: engine.CalcDifficulty(&fakeChainReader{config}, parent.Time().Uint64()+10, &types.Header{
+		Difficulty: engine.CalcDifficulty(&fakeChainReader{config}, parent.Time()+10, &types.Header{
 			Number:     parent.Number(),
 			Time:       parent.Time(),
 			Difficulty: parent.Difficulty(),
@@ -264,7 +264,7 @@ func GenerateBadBlock(t *testing.T, parent *types.Block, engine consensus.Engine
 		}),
 		GasLimit:  parent.GasLimit(),
 		Number:    new(big.Int).Add(parent.Number(), common.Big1),
-		Time:      new(big.Int).SetUint64(parent.Time().Uint64() + 10),
+		Time:      parent.Time() + 10,
 		UncleHash: types.EmptyUncleHash,
 	}
 	if config.IsEIP1559(header.Number) {
diff --git a/core/types/block.go b/core/types/block.go
index 93d71d3974..bd07d5e7c8 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -22,10 +22,10 @@ import (
 	"fmt"
 	"io"
 	"math/big"
+	"reflect"
 	"sort"
 	"sync/atomic"
 	"time"
-	"unsafe"
 
 	"github.com/XinFinOrg/XDPoSChain/common"
 	"github.com/XinFinOrg/XDPoSChain/common/hexutil"
@@ -74,7 +74,7 @@ type Header struct {
 	Number      *big.Int       `json:"number"           gencodec:"required"`
 	GasLimit    uint64         `json:"gasLimit"         gencodec:"required"`
 	GasUsed     uint64         `json:"gasUsed"          gencodec:"required"`
-	Time        *big.Int       `json:"timestamp"        gencodec:"required"`
+	Time        uint64         `json:"timestamp"        gencodec:"required"`
 	Extra       []byte         `json:"extraData"        gencodec:"required"`
 	MixDigest   common.Hash    `json:"mixHash"          gencodec:"required"`
 	Nonce       BlockNonce     `json:"nonce"            gencodec:"required"`
@@ -92,7 +92,7 @@ type headerMarshaling struct {
 	Number     *hexutil.Big
 	GasLimit   hexutil.Uint64
 	GasUsed    hexutil.Uint64
-	Time       *hexutil.Big
+	Time       hexutil.Uint64
 	Extra      hexutil.Bytes
 	BaseFee    *hexutil.Big
 	Hash       common.Hash `json:"hash"` // adds call to Hash() in MarshalJSON
@@ -147,10 +147,16 @@ func (h *Header) HashNoValidator() common.Hash {
 	})
 }
 
+var headerSize = common.StorageSize(reflect.TypeOf(Header{}).Size())
+
 // Size returns the approximate memory used by all internal contents. It is used
 // to approximate and limit the memory consumption of various caches.
 func (h *Header) Size() common.StorageSize {
-	return common.StorageSize(unsafe.Sizeof(*h)) + common.StorageSize(len(h.Extra)+(h.Difficulty.BitLen()+h.Number.BitLen()+h.Time.BitLen())/8)
+	var baseFeeBits int
+	if h.BaseFee != nil {
+		baseFeeBits = h.BaseFee.BitLen()
+	}
+	return headerSize + common.StorageSize(len(h.Extra)+len(h.Validators)+len(h.Validator)+len(h.Penalties)+(h.Difficulty.BitLen()+h.Number.BitLen()+baseFeeBits)/8)
 }
 
 // EmptyBody returns true if there is no additional 'body' to complete the header
@@ -270,9 +276,6 @@ func NewBlockWithHeader(header *Header) *Block {
 // modifying a header variable.
 func CopyHeader(h *Header) *Header {
 	cpy := *h
-	if cpy.Time = new(big.Int); h.Time != nil {
-		cpy.Time.Set(h.Time)
-	}
 	if cpy.Difficulty = new(big.Int); h.Difficulty != nil {
 		cpy.Difficulty.Set(h.Difficulty)
 	}
@@ -286,10 +289,18 @@ func CopyHeader(h *Header) *Header {
 		cpy.Extra = make([]byte, len(h.Extra))
 		copy(cpy.Extra, h.Extra)
 	}
+	if len(h.Validators) > 0 {
+		cpy.Validators = make([]byte, len(h.Validators))
+		copy(cpy.Validators, h.Validators)
+	}
 	if len(h.Validator) > 0 {
 		cpy.Validator = make([]byte, len(h.Validator))
 		copy(cpy.Validator, h.Validator)
 	}
+	if len(h.Penalties) > 0 {
+		cpy.Penalties = make([]byte, len(h.Penalties))
+		copy(cpy.Penalties, h.Penalties)
+	}
 	return &cpy
 }
 
@@ -342,7 +353,7 @@ func (b *Block) Number() *big.Int     { return new(big.Int).Set(b.header.Number)
 func (b *Block) GasLimit() uint64     { return b.header.GasLimit }
 func (b *Block) GasUsed() uint64      { return b.header.GasUsed }
 func (b *Block) Difficulty() *big.Int { return new(big.Int).Set(b.header.Difficulty) }
-func (b *Block) Time() *big.Int       { return new(big.Int).Set(b.header.Time) }
+func (b *Block) Time() uint64         { return b.header.Time }
 
 func (b *Block) NumberU64() uint64        { return b.header.Number.Uint64() }
 func (b *Block) MixDigest() common.Hash   { return b.header.MixDigest }
diff --git a/core/types/block_test.go b/core/types/block_test.go
index 4c496b2901..91eabbadba 100644
--- a/core/types/block_test.go
+++ b/core/types/block_test.go
@@ -52,7 +52,7 @@ func TestBlockEncoding(t *testing.T) {
 	check("Root", block.Root().String(), common.HexToHash("ef1552a40b7165c3cd773806b9e0c165b75356e0314bf0706f279c729f51e017").String())
 	check("Hash", block.Hash().String(), common.HexToHash("e8d9d473fdeddd3079988fa7be58f582b7b2800e90917d4bb6f11155ce4dba30").String())
 	check("Nonce", block.Nonce(), uint64(0xa13a5a8c8f2bb1c4))
-	check("Time", block.Time(), big.NewInt(1426516743))
+	check("Time", block.Time(), uint64(1426516743))
 	check("Size", block.Size(), common.StorageSize(len(blockEnc)))
 
 	ourBlockEnc, err := rlp.EncodeToBytes(&block)
@@ -84,7 +84,7 @@ func TestEIP2718BlockEncoding(t *testing.T) {
 	check("MixDigest", block.MixDigest(), common.HexToHash("bd4472abb6659ebe3ee06ee4d7b72a00a9f4d001caca51342001075469aff498"))
 	check("Root", block.Root(), common.HexToHash("ef1552a40b7165c3cd773806b9e0c165b75356e0314bf0706f279c729f51e017"))
 	check("Nonce", block.Nonce(), uint64(0xa13a5a8c8f2bb1c4))
-	check("Time", block.Time().Uint64(), uint64(1426516743))
+	check("Time", block.Time(), uint64(1426516743))
 	check("Size", block.Size(), common.StorageSize(len(blockEnc)))
 
 	// Create legacy tx.
@@ -186,7 +186,7 @@ func makeBenchBlock() *Block {
 		Number:     math.BigPow(2, 9),
 		GasLimit:   12345678,
 		GasUsed:    1476322,
-		Time:       big.NewInt(9876543),
+		Time:       9876543,
 		Extra:      []byte("coolest block on chain"),
 	}
 	for i := range txs {
@@ -207,7 +207,7 @@ func makeBenchBlock() *Block {
 			Number:     math.BigPow(2, 9),
 			GasLimit:   12345678,
 			GasUsed:    1476322,
-			Time:       big.NewInt(9876543),
+			Time:       9876543,
 			Extra:      []byte("benchmark uncle"),
 		}
 	}
diff --git a/core/types/gen_header_json.go b/core/types/gen_header_json.go
index 4f8b851b36..05889cdc30 100644
--- a/core/types/gen_header_json.go
+++ b/core/types/gen_header_json.go
@@ -27,7 +27,7 @@ func (h Header) MarshalJSON() ([]byte, error) {
 		Number      *hexutil.Big   `json:"number"           gencodec:"required"`
 		GasLimit    hexutil.Uint64 `json:"gasLimit"         gencodec:"required"`
 		GasUsed     hexutil.Uint64 `json:"gasUsed"          gencodec:"required"`
-		Time        *hexutil.Big   `json:"timestamp"        gencodec:"required"`
+		Time        hexutil.Uint64 `json:"timestamp"        gencodec:"required"`
 		Extra       hexutil.Bytes  `json:"extraData"        gencodec:"required"`
 		MixDigest   common.Hash    `json:"mixHash"          gencodec:"required"`
 		Nonce       BlockNonce     `json:"nonce"            gencodec:"required"`
@@ -49,7 +49,7 @@ func (h Header) MarshalJSON() ([]byte, error) {
 	enc.Number = (*hexutil.Big)(h.Number)
 	enc.GasLimit = hexutil.Uint64(h.GasLimit)
 	enc.GasUsed = hexutil.Uint64(h.GasUsed)
-	enc.Time = (*hexutil.Big)(h.Time)
+	enc.Time = hexutil.Uint64(h.Time)
 	enc.Extra = h.Extra
 	enc.MixDigest = h.MixDigest
 	enc.Nonce = h.Nonce
@@ -75,7 +75,7 @@ func (h *Header) UnmarshalJSON(input []byte) error {
 		Number      *hexutil.Big    `json:"number"           gencodec:"required"`
 		GasLimit    *hexutil.Uint64 `json:"gasLimit"         gencodec:"required"`
 		GasUsed     *hexutil.Uint64 `json:"gasUsed"          gencodec:"required"`
-		Time        *hexutil.Big    `json:"timestamp"        gencodec:"required"`
+		Time        *hexutil.Uint64 `json:"timestamp"        gencodec:"required"`
 		Extra       *hexutil.Bytes  `json:"extraData"        gencodec:"required"`
 		MixDigest   *common.Hash    `json:"mixHash"          gencodec:"required"`
 		Nonce       *BlockNonce     `json:"nonce"            gencodec:"required"`
@@ -135,7 +135,7 @@ func (h *Header) UnmarshalJSON(input []byte) error {
 	if dec.Time == nil {
 		return errors.New("missing required field 'timestamp' for Header")
 	}
-	h.Time = (*big.Int)(dec.Time)
+	h.Time = uint64(*dec.Time)
 	if dec.Extra == nil {
 		return errors.New("missing required field 'extraData' for Header")
 	}
diff --git a/core/vm/runtime/runtime_test.go b/core/vm/runtime/runtime_test.go
index 87e1bac529..386b42b5bc 100644
--- a/core/vm/runtime/runtime_test.go
+++ b/core/vm/runtime/runtime_test.go
@@ -217,7 +217,7 @@ func fakeHeader(n uint64, parentHash common.Hash) *types.Header {
 		Coinbase:   common.HexToAddress("0x00000000000000000000000000000000deadbeef"),
 		Number:     big.NewInt(int64(n)),
 		ParentHash: parentHash,
-		Time:       big.NewInt(1000),
+		Time:       1000,
 		Nonce:      types.BlockNonce{0x1},
 		Extra:      []byte{},
 		Difficulty: big.NewInt(0),
diff --git a/eth/api_backend.go b/eth/api_backend.go
index df10cb6c2a..3569012186 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -577,7 +577,7 @@ func (b *EthAPIBackend) GetEpochDuration() *big.Int {
 	secondToLastCheckpointNumber := lastCheckpointNumber - b.ChainConfig().XDPoS.Epoch
 	secondToLastCheckpointBlockTime := chain.GetBlockByNumber(secondToLastCheckpointNumber).Time()
 
-	return secondToLastCheckpointBlockTime.Add(secondToLastCheckpointBlockTime, lastCheckpointBlockTime.Mul(lastCheckpointBlockTime, new(big.Int).SetInt64(-1)))
+	return new(big.Int).SetInt64(int64(secondToLastCheckpointBlockTime) - int64(lastCheckpointBlockTime))
 }
 
 // GetMasternodesCap return a cap of all masternode at a checkpoint
diff --git a/eth/fetcher/fetcher.go b/eth/fetcher/fetcher.go
index c4aa795532..04e9f9861d 100644
--- a/eth/fetcher/fetcher.go
+++ b/eth/fetcher/fetcher.go
@@ -689,7 +689,7 @@ func (f *Fetcher) insert(peer string, block *types.Block) {
 				go f.broadcastBlock(block, true)
 			}
 		case consensus.ErrFutureBlock:
-			delay := time.Until(time.Unix(block.Time().Int64(), 0))
+			delay := time.Until(time.Unix(int64(block.Time()), 0))
 			log.Info("Receive future block", "number", block.NumberU64(), "hash", block.Hash().Hex(), "delay", delay)
 			time.Sleep(delay)
 			goto again
diff --git a/ethstats/ethstats.go b/ethstats/ethstats.go
index 4f3af91e1d..0e69a00251 100644
--- a/ethstats/ethstats.go
+++ b/ethstats/ethstats.go
@@ -672,7 +672,7 @@ func (s *Service) assembleBlockStats(block *types.Block) *blockStats {
 		Number:     header.Number,
 		Hash:       header.Hash(),
 		ParentHash: header.ParentHash,
-		Timestamp:  header.Time,
+		Timestamp:  new(big.Int).SetUint64(header.Time),
 		Miner:      author,
 		GasUsed:    header.GasUsed,
 		GasLimit:   header.GasLimit,
diff --git a/internal/ethapi/api.go b/internal/ethapi/api.go
index c79e6749c2..acac735cbf 100644
--- a/internal/ethapi/api.go
+++ b/internal/ethapi/api.go
@@ -1379,7 +1379,7 @@ func RPCMarshalHeader(head *types.Header) map[string]interface{} {
 		"size":             hexutil.Uint64(head.Size()),
 		"gasLimit":         hexutil.Uint64(head.GasLimit),
 		"gasUsed":          hexutil.Uint64(head.GasUsed),
-		"timestamp":        (*hexutil.Big)(head.Time),
+		"timestamp":        hexutil.Uint64(head.Time),
 		"transactionsRoot": head.TxHash,
 		"receiptsRoot":     head.ReceiptHash,
 		"validators":       hexutil.Bytes(head.Validators),
diff --git a/internal/ethapi/transaction_args_test.go b/internal/ethapi/transaction_args_test.go
index 16de689df1..e34d3a2934 100644
--- a/internal/ethapi/transaction_args_test.go
+++ b/internal/ethapi/transaction_args_test.go
@@ -261,7 +261,7 @@ func newBackendMock() *backendMock {
 			Number:     big.NewInt(1100),
 			GasLimit:   8_000_000,
 			GasUsed:    8_000_000,
-			Time:       big.NewInt(555),
+			Time:       555,
 			Extra:      make([]byte, 32),
 			BaseFee:    big.NewInt(10),
 		},
diff --git a/miner/worker.go b/miner/worker.go
index 1d6ef32784..8b6ca93d4d 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -383,7 +383,7 @@ func (w *worker) update() {
 
 func getResetTime(chain *core.BlockChain, minePeriod int) time.Duration {
 	minePeriodDuration := time.Duration(minePeriod) * time.Second
-	currentBlockTime := chain.CurrentBlock().Time().Int64()
+	currentBlockTime := int64(chain.CurrentBlock().Time())
 	nowTime := time.Now().UnixMilli()
 	resetTime := time.Duration(currentBlockTime)*time.Second + minePeriodDuration - time.Duration(nowTime)*time.Millisecond
 	// in case the current block time is not very accurate
@@ -639,8 +639,8 @@ func (w *worker) commitNewWork() {
 		}
 	}
 	tstamp := tstart.Unix()
-	if parent.Time().Cmp(new(big.Int).SetInt64(tstamp)) >= 0 {
-		tstamp = parent.Time().Int64() + 1
+	if parent.Time() >= uint64(tstamp) {
+		tstamp = int64(parent.Time() + 1)
 	}
 	// this will ensure we're not going off too far in the future
 	if now := time.Now().Unix(); tstamp > now {
@@ -655,7 +655,7 @@ func (w *worker) commitNewWork() {
 		Number:     num.Add(num, common.Big1),
 		GasLimit:   params.TargetGasLimit,
 		Extra:      w.extra,
-		Time:       big.NewInt(tstamp),
+		Time:       uint64(tstamp),
 	}
 	// Set baseFee if we are on an EIP-1559 chain
 	header.BaseFee = eip1559.CalcBaseFee(w.config, header)
diff --git a/tests/block_test_util.go b/tests/block_test_util.go
index 75a43d0921..f0155d2d48 100644
--- a/tests/block_test_util.go
+++ b/tests/block_test_util.go
@@ -81,7 +81,7 @@ type btHeader struct {
 	Difficulty       *big.Int
 	GasLimit         uint64
 	GasUsed          uint64
-	Timestamp        *big.Int
+	Timestamp        uint64
 	BaseFee          *big.Int
 }
 
@@ -91,7 +91,7 @@ type btHeaderMarshaling struct {
 	Difficulty *math.HexOrDecimal256
 	GasLimit   math.HexOrDecimal64
 	GasUsed    math.HexOrDecimal64
-	Timestamp  *math.HexOrDecimal256
+	Timestamp  math.HexOrDecimal64
 	BaseFee    *math.HexOrDecimal256
 }
 
@@ -142,7 +142,7 @@ func (t *BlockTest) genesis(config *params.ChainConfig) *core.Genesis {
 	return &core.Genesis{
 		Config:     config,
 		Nonce:      t.json.Genesis.Nonce.Uint64(),
-		Timestamp:  t.json.Genesis.Timestamp.Uint64(),
+		Timestamp:  t.json.Genesis.Timestamp,
 		ParentHash: t.json.Genesis.ParentHash,
 		ExtraData:  t.json.Genesis.ExtraData,
 		GasLimit:   t.json.Genesis.GasLimit,
@@ -251,7 +251,7 @@ func validateHeader(h *btHeader, h2 *types.Header) error {
 	if h.GasUsed != h2.GasUsed {
 		return fmt.Errorf("mismatch GasUsed: want: %d have: %d", h.GasUsed, h2.GasUsed)
 	}
-	if h.Timestamp.Cmp(h2.Time) != 0 {
+	if h.Timestamp != h2.Time {
 		return fmt.Errorf("mismatch Timestamp: want: %v have: %v", h.Timestamp, h2.Time)
 	}
 	return nil
diff --git a/tests/difficulty_test_util.go b/tests/difficulty_test_util.go
index 9b628fa2d6..4af91a2206 100644
--- a/tests/difficulty_test_util.go
+++ b/tests/difficulty_test_util.go
@@ -30,18 +30,18 @@ import (
 //go:generate go run github.com/fjl/gencodec -type DifficultyTest -field-override difficultyTestMarshaling -out gen_difficultytest.go
 
 type DifficultyTest struct {
-	ParentTimestamp    *big.Int    `json:"parentTimestamp"`
+	ParentTimestamp    uint64      `json:"parentTimestamp"`
 	ParentDifficulty   *big.Int    `json:"parentDifficulty"`
 	UncleHash          common.Hash `json:"parentUncles"`
-	CurrentTimestamp   *big.Int    `json:"currentTimestamp"`
+	CurrentTimestamp   uint64      `json:"currentTimestamp"`
 	CurrentBlockNumber uint64      `json:"currentBlockNumber"`
 	CurrentDifficulty  *big.Int    `json:"currentDifficulty"`
 }
 
 type difficultyTestMarshaling struct {
-	ParentTimestamp    *math.HexOrDecimal256
+	ParentTimestamp    math.HexOrDecimal64
 	ParentDifficulty   *math.HexOrDecimal256
-	CurrentTimestamp   *math.HexOrDecimal256
+	CurrentTimestamp   math.HexOrDecimal64
 	CurrentDifficulty  *math.HexOrDecimal256
 	UncleHash          common.Hash
 	CurrentBlockNumber math.HexOrDecimal64
@@ -56,7 +56,7 @@ func (test *DifficultyTest) Run(config *params.ChainConfig) error {
 		UncleHash:  test.UncleHash,
 	}
 
-	actual := ethash.CalcDifficulty(config, test.CurrentTimestamp.Uint64(), parent)
+	actual := ethash.CalcDifficulty(config, test.CurrentTimestamp, parent)
 	exp := test.CurrentDifficulty
 
 	if actual.Cmp(exp) != 0 {
diff --git a/tests/gen_btheader.go b/tests/gen_btheader.go
index abe99159cc..642d2dde75 100644
--- a/tests/gen_btheader.go
+++ b/tests/gen_btheader.go
@@ -32,7 +32,7 @@ func (b btHeader) MarshalJSON() ([]byte, error) {
 		Difficulty       *math.HexOrDecimal256
 		GasLimit         math.HexOrDecimal64
 		GasUsed          math.HexOrDecimal64
-		Timestamp        *math.HexOrDecimal256
+		Timestamp        math.HexOrDecimal64
 		BaseFee          *math.HexOrDecimal256
 	}
 	var enc btHeader
@@ -51,7 +51,7 @@ func (b btHeader) MarshalJSON() ([]byte, error) {
 	enc.Difficulty = (*math.HexOrDecimal256)(b.Difficulty)
 	enc.GasLimit = math.HexOrDecimal64(b.GasLimit)
 	enc.GasUsed = math.HexOrDecimal64(b.GasUsed)
-	enc.Timestamp = (*math.HexOrDecimal256)(b.Timestamp)
+	enc.Timestamp = math.HexOrDecimal64(b.Timestamp)
 	enc.BaseFee = (*math.HexOrDecimal256)(b.BaseFee)
 	return json.Marshal(&enc)
 }
@@ -74,7 +74,7 @@ func (b *btHeader) UnmarshalJSON(input []byte) error {
 		Difficulty       *math.HexOrDecimal256
 		GasLimit         *math.HexOrDecimal64
 		GasUsed          *math.HexOrDecimal64
-		Timestamp        *math.HexOrDecimal256
+		Timestamp        *math.HexOrDecimal64
 		BaseFee          *math.HexOrDecimal256
 	}
 	var dec btHeader
@@ -127,7 +127,7 @@ func (b *btHeader) UnmarshalJSON(input []byte) error {
 		b.GasUsed = uint64(*dec.GasUsed)
 	}
 	if dec.Timestamp != nil {
-		b.Timestamp = (*big.Int)(dec.Timestamp)
+		b.Timestamp = uint64(*dec.Timestamp)
 	}
 	if dec.BaseFee != nil {
 		b.BaseFee = (*big.Int)(dec.BaseFee)
diff --git a/tests/gen_difficultytest.go b/tests/gen_difficultytest.go
index 67ce089e3c..83e6b8a1cb 100644
--- a/tests/gen_difficultytest.go
+++ b/tests/gen_difficultytest.go
@@ -15,18 +15,18 @@ var _ = (*difficultyTestMarshaling)(nil)
 // MarshalJSON marshals as JSON.
 func (d DifficultyTest) MarshalJSON() ([]byte, error) {
 	type DifficultyTest struct {
-		ParentTimestamp    *math.HexOrDecimal256 `json:"parentTimestamp"`
+		ParentTimestamp    math.HexOrDecimal64   `json:"parentTimestamp"`
 		ParentDifficulty   *math.HexOrDecimal256 `json:"parentDifficulty"`
 		UncleHash          common.Hash           `json:"parentUncles"`
-		CurrentTimestamp   *math.HexOrDecimal256 `json:"currentTimestamp"`
+		CurrentTimestamp   math.HexOrDecimal64   `json:"currentTimestamp"`
 		CurrentBlockNumber math.HexOrDecimal64   `json:"currentBlockNumber"`
 		CurrentDifficulty  *math.HexOrDecimal256 `json:"currentDifficulty"`
 	}
 	var enc DifficultyTest
-	enc.ParentTimestamp = (*math.HexOrDecimal256)(d.ParentTimestamp)
+	enc.ParentTimestamp = math.HexOrDecimal64(d.ParentTimestamp)
 	enc.ParentDifficulty = (*math.HexOrDecimal256)(d.ParentDifficulty)
 	enc.UncleHash = d.UncleHash
-	enc.CurrentTimestamp = (*math.HexOrDecimal256)(d.CurrentTimestamp)
+	enc.CurrentTimestamp = math.HexOrDecimal64(d.CurrentTimestamp)
 	enc.CurrentBlockNumber = math.HexOrDecimal64(d.CurrentBlockNumber)
 	enc.CurrentDifficulty = (*math.HexOrDecimal256)(d.CurrentDifficulty)
 	return json.Marshal(&enc)
@@ -35,10 +35,10 @@ func (d DifficultyTest) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON unmarshals from JSON.
 func (d *DifficultyTest) UnmarshalJSON(input []byte) error {
 	type DifficultyTest struct {
-		ParentTimestamp    *math.HexOrDecimal256 `json:"parentTimestamp"`
+		ParentTimestamp    *math.HexOrDecimal64  `json:"parentTimestamp"`
 		ParentDifficulty   *math.HexOrDecimal256 `json:"parentDifficulty"`
 		UncleHash          *common.Hash          `json:"parentUncles"`
-		CurrentTimestamp   *math.HexOrDecimal256 `json:"currentTimestamp"`
+		CurrentTimestamp   *math.HexOrDecimal64  `json:"currentTimestamp"`
 		CurrentBlockNumber *math.HexOrDecimal64  `json:"currentBlockNumber"`
 		CurrentDifficulty  *math.HexOrDecimal256 `json:"currentDifficulty"`
 	}
@@ -47,7 +47,7 @@ func (d *DifficultyTest) UnmarshalJSON(input []byte) error {
 		return err
 	}
 	if dec.ParentTimestamp != nil {
-		d.ParentTimestamp = (*big.Int)(dec.ParentTimestamp)
+		d.ParentTimestamp = uint64(*dec.ParentTimestamp)
 	}
 	if dec.ParentDifficulty != nil {
 		d.ParentDifficulty = (*big.Int)(dec.ParentDifficulty)
@@ -56,7 +56,7 @@ func (d *DifficultyTest) UnmarshalJSON(input []byte) error {
 		d.UncleHash = *dec.UncleHash
 	}
 	if dec.CurrentTimestamp != nil {
-		d.CurrentTimestamp = (*big.Int)(dec.CurrentTimestamp)
+		d.CurrentTimestamp = uint64(*dec.CurrentTimestamp)
 	}
 	if dec.CurrentBlockNumber != nil {
 		d.CurrentBlockNumber = uint64(*dec.CurrentBlockNumber)