diff --git a/contracts/tokens/ERC721/ERC721EXPBase.sol b/contracts/tokens/ERC721/ERC721EXPBase.sol
index acccef4..9fe0034 100644
--- a/contracts/tokens/ERC721/ERC721EXPBase.sol
+++ b/contracts/tokens/ERC721/ERC721EXPBase.sol
@@ -47,7 +47,7 @@ abstract contract ERC721EXPBase is ERC721, ERC721Enumerable, IERC7858 {
     }
 
     function _updateTimeStamp(uint256 tokenId, uint64 start, uint64 end) internal {
-        if ((start <= end) && (start != 0) && (end != 0)) {
+        if (start >= end) {
             revert ERC7858InvalidTimeStamp(start, end);
         }
         _tokensTimeStamp[tokenId].start = start;
diff --git a/contracts/tokens/ERC721/interfaces/IERC7858.sol b/contracts/tokens/ERC721/interfaces/IERC7858.sol
index e010632..c3425bf 100644
--- a/contracts/tokens/ERC721/interfaces/IERC7858.sol
+++ b/contracts/tokens/ERC721/interfaces/IERC7858.sol
@@ -15,11 +15,7 @@ interface IERC7858 {
      * @param startTime The start time of the token (block number or timestamp based on `expiryType`).
      * @param endTime The end time of the token (block number or timestamp based on `expiryType`).
      */
-    event TokenExpiryUpdated(
-        uint256 indexed tokenId,
-        uint256 indexed startTime,
-        uint256 indexed endTime
-    );
+    event TokenExpiryUpdated(uint256 indexed tokenId, uint256 indexed startTime, uint256 indexed endTime);
 
     error ERC7858InvalidTimeStamp(uint256 start, uint256 end);