diff --git a/.github/workflows/performance.yml b/.github/workflows/performance.yml
index 913ada9ac256e..7eb26466019e1 100644
--- a/.github/workflows/performance.yml
+++ b/.github/workflows/performance.yml
@@ -87,7 +87,7 @@ jobs:
               env:
                   CODEHEALTH_PROJECT_TOKEN: ${{ secrets.CODEHEALTH_PROJECT_TOKEN }}
               run: |
-                  COMMITTED_AT=$(git show -s $GITHUB_SHA --format="%ct")
+                  COMMITTED_AT=$(git show -s $GITHUB_SHA --format="%cI")
                   ./bin/log-performance-results.js $CODEHEALTH_PROJECT_TOKEN trunk $GITHUB_SHA 34af5829ac9edb31833167ff6a3b51bea982999c $COMMITTED_AT
 
             - name: Archive debug artifacts (screenshots, HTML snapshots)
diff --git a/bin/log-performance-results.js b/bin/log-performance-results.js
index 9bc7ef9cb99b1..861e09bbc6c4d 100755
--- a/bin/log-performance-results.js
+++ b/bin/log-performance-results.js
@@ -37,7 +37,7 @@ const data = new TextEncoder().encode(
 		branch,
 		hash,
 		baseHash,
-		timestamp: parseInt( timestamp, 10 ),
+		timestamp,
 		metrics: resultsFiles.reduce( ( result, { metricsPrefix }, index ) => {
 			return {
 				...result,