diff --git a/dist/index.js b/dist/index.js
index 0b4c5bf..9ad1763 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -16400,7 +16400,7 @@ async function fetchDiff(pull) {
     const divergedFrom = await git.raw('rev-list', '--max-parents=0', 'HEAD');
     const divergedAt = await git.show([
         '--quiet',
-        '--date=iso8601',
+        '--date=unix',
         '--format=%cd',
         divergedFrom
     ]);
diff --git a/src/initializer.ts b/src/initializer.ts
index 296631a..34e1992 100644
--- a/src/initializer.ts
+++ b/src/initializer.ts
@@ -59,7 +59,7 @@ export async function fetchDiff(pull: PullRequest): Promise<string> {
   const divergedFrom = await git.raw('rev-list', '--max-parents=0', 'HEAD')
   const divergedAt = await git.show([
     '--quiet',
-    '--date=iso8601',
+    '--date=unix',
     '--format=%cd',
     divergedFrom
   ])