diff --git a/certora/specs/Marketplace.spec b/certora/specs/Marketplace.spec
index 64ba147..48f3564 100644
--- a/certora/specs/Marketplace.spec
+++ b/certora/specs/Marketplace.spec
@@ -5,7 +5,7 @@ using ERC20A as Token;
 methods {
     function Token.balanceOf(address) external returns (uint256) envfree;
     function Token.totalSupply() external returns (uint256) envfree;
-    function publicPeriodEnd(Periods.Period) external returns (uint64) envfree;
+    function publicPeriodEnd(Periods.Period) external returns (Marketplace.Timestamp) envfree;
     function generateSlotId(Marketplace.RequestId, uint64) external returns (Marketplace.SlotId) envfree;
 }
 
diff --git a/contracts/Configuration.sol b/contracts/Configuration.sol
index dd70be4..10d697a 100644
--- a/contracts/Configuration.sol
+++ b/contracts/Configuration.sol
@@ -20,8 +20,8 @@ struct CollateralConfig {
 }
 
 struct ProofConfig {
-  uint64 period; // proofs requirements are calculated per period (in seconds)
-  uint64 timeout; // mark proofs as missing before the timeout (in seconds)
+  Duration period; // proofs requirements are calculated per period (in seconds)
+  Duration timeout; // mark proofs as missing before the timeout (in seconds)
   uint8 downtime; // ignore this much recent blocks for proof requirements
   // Ensures the pointer does not remain in downtime for many consecutive
   // periods. For each period increase, move the pointer `pointerProduct`
diff --git a/contracts/Periods.sol b/contracts/Periods.sol
index 5e18ee1..189fb02 100644
--- a/contracts/Periods.sol
+++ b/contracts/Periods.sol
@@ -1,37 +1,45 @@
 // SPDX-License-Identifier: MIT
 pragma solidity 0.8.28;
 
+import "./Timestamps.sol";
+
 contract Periods {
   error Periods_InvalidSecondsPerPeriod();
 
-  type Period is uint64;
+  type Period is uint40;
 
-  uint64 internal immutable _secondsPerPeriod;
+  Duration internal immutable _secondsPerPeriod;
 
-  constructor(uint64 secondsPerPeriod) {
-    if (secondsPerPeriod == 0) {
+  constructor(Duration secondsPerPeriod) {
+    if (secondsPerPeriod == Duration.wrap(0)) {
       revert Periods_InvalidSecondsPerPeriod();
     }
     _secondsPerPeriod = secondsPerPeriod;
   }
 
-  function _periodOf(uint64 timestamp) internal view returns (Period) {
-    return Period.wrap(timestamp / _secondsPerPeriod);
+  function _periodOf(Timestamp timestamp) internal view returns (Period) {
+    return
+      Period.wrap(
+        Timestamp.unwrap(timestamp) / Duration.unwrap(_secondsPerPeriod)
+      );
   }
 
   function _blockPeriod() internal view returns (Period) {
-    return _periodOf(uint64(block.timestamp));
+    return _periodOf(Timestamps.currentTime());
   }
 
   function _nextPeriod(Period period) internal pure returns (Period) {
     return Period.wrap(Period.unwrap(period) + 1);
   }
 
-  function _periodStart(Period period) internal view returns (uint64) {
-    return Period.unwrap(period) * _secondsPerPeriod;
+  function _periodStart(Period period) internal view returns (Timestamp) {
+    return
+      Timestamp.wrap(
+        Period.unwrap(period) * Duration.unwrap(_secondsPerPeriod)
+      );
   }
 
-  function _periodEnd(Period period) internal view returns (uint64) {
+  function _periodEnd(Period period) internal view returns (Timestamp) {
     return _periodStart(_nextPeriod(period));
   }
 
diff --git a/contracts/Proofs.sol b/contracts/Proofs.sol
index f48b377..87da0cc 100644
--- a/contracts/Proofs.sol
+++ b/contracts/Proofs.sol
@@ -3,6 +3,7 @@ pragma solidity 0.8.28;
 
 import "./Configuration.sol";
 import "./Requests.sol";
+import "./Timestamps.sol";
 import "./Periods.sol";
 import "./Groth16.sol";
 
@@ -11,6 +12,8 @@ import "./Groth16.sol";
  * @notice Abstract contract that handles proofs tracking, validation and reporting functionality
  */
 abstract contract Proofs is Periods {
+  using Timestamps for Timestamp;
+
   error Proofs_InsufficientBlockHeight();
   error Proofs_InvalidProof();
   error Proofs_ProofAlreadySubmitted();
@@ -39,7 +42,7 @@ abstract contract Proofs is Periods {
     _verifier = verifier;
   }
 
-  mapping(SlotId => uint64) private _slotStarts;
+  mapping(SlotId => Timestamp) private _slotStarts;
   mapping(SlotId => uint64) private _missed;
   mapping(SlotId => mapping(Period => bool)) private _received;
   mapping(SlotId => mapping(Period => bool)) private _missing;
@@ -73,7 +76,7 @@ abstract contract Proofs is Periods {
    *     and saves the required probability.
    */
   function _startRequiringProofs(SlotId id) internal {
-    _slotStarts[id] = uint64(block.timestamp);
+    _slotStarts[id] = Timestamps.currentTime();
   }
 
   /**
@@ -224,10 +227,10 @@ abstract contract Proofs is Periods {
    *    - proof was already marked as missing
    */
   function _markProofAsMissing(SlotId id, Period missedPeriod) internal {
-    uint256 end = _periodEnd(missedPeriod);
-    if (end >= block.timestamp) revert Proofs_PeriodNotEnded();
-    if (block.timestamp >= end + _config.timeout)
-      revert Proofs_ValidationTimedOut();
+    Timestamp end = _periodEnd(missedPeriod);
+    Timestamp current = Timestamps.currentTime();
+    if (current <= end) revert Proofs_PeriodNotEnded();
+    if (end.add(_config.timeout) <= current) revert Proofs_ValidationTimedOut();
     if (_received[id][missedPeriod]) revert Proofs_ProofNotMissing();
     if (!_isProofRequired(id, missedPeriod)) revert Proofs_ProofNotRequired();
     if (_missing[id][missedPeriod]) revert Proofs_ProofAlreadyMarkedMissing();