diff --git a/src/providers/bedrock/utils.ts b/src/providers/bedrock/utils.ts
index 40b72983d..ec776d351 100644
--- a/src/providers/bedrock/utils.ts
+++ b/src/providers/bedrock/utils.ts
@@ -280,7 +280,8 @@ export async function getAssumedRoleCredentials(
     sha256: Sha256,
   });
   const date = new Date();
-  const sessionName = `${date.getFullYear()}${date.getMonth()}${date.getDay()}`;
+  // YYYYMMDD; RoleSessionName is visible in CloudTrail and the CUR's line-item identity
+  const sessionName = date.toISOString().slice(0, 10).replace(/-/g, '');
   const url = `https://${hostname}?Action=AssumeRole&Version=2011-06-15&RoleArn=${awsRoleArn}&RoleSessionName=${sessionName}${awsExternalId ? `&ExternalId=${awsExternalId}` : ''}`;
   const urlObj = new URL(url);
   const requestHeaders = { host: hostname };