try setupFiles

Author: alexnuttall

frontend/jest.config.ts

@@ -42,6 +42,7 @@ const config: Config = {
   },
 
   setupFilesAfterEnv: ['<rootDir>/jest.setup.ts'],
+  setupFiles: ['<rootDir>/jest.tz-setup.ts'],
 };
 
 // createJestConfig is exported this way to ensure that next/jest can load the Next.js config which is async

frontend/jest.setup.ts

@@ -35,6 +35,3 @@ createMocks();
 if (typeof window !== 'undefined') {
   window.HTMLElement.prototype.scrollIntoView = jest.fn();
 }
-
-// Pin timezone for deterministic date rendering
-process.env.TZ = 'Europe/London';

frontend/jest.tz-setup.ts

@@ -0,0 +1,2 @@
+// pin TZ for deterministic date rendering
+process.env.TZ = 'Europe/London';