diff --git a/test/relative-time.js b/test/relative-time.js
index f497327..d71be12 100644
--- a/test/relative-time.js
+++ b/test/relative-time.js
@@ -270,7 +270,7 @@ suite('relative-time', function () {
 
   suite('[threshold]', function () {
     test('switches to dates after 30 past days with default threshold', async () => {
-      const now = new Date(Date.now() - 31 * 60 * 60 * 24 * 1000).toISOString()
+      const now = new Date(Date.now() - 32 * 60 * 60 * 24 * 1000).toISOString()
       const time = document.createElement('relative-time')
       time.setAttribute('lang', 'en-US')
       time.setAttribute('datetime', now)