dateFormat.setTimeZone(TimeZone.getTimeZone("UTC")); body.putString("date", dateFormat.format(new Date())); body.putString("value", TimeZone.getDefault().getID()); getReactApplicationContext() .getJSModule(RCTDeviceEventEmitter.class) .emit("timeZoneChange", body); import { NativeEventEmitter, NativeModules } from "react-native"; const emitter = new NativeEventEmitter(NativeModules.RNModuleTemplate); type Listeners = { timeZoneChange: (body: { date: string; value: string }) = > void; }; export function addListener<Type extends keyof Listeners>( type: Type, listener: Listeners[Type], ): () = > void { const subscription = emitter.addListener(type, listener); return subscription.remove; } Java TypeScript