Many of the interfaces in the Obsidian lets you subscribe to events throughout the application, for example when the user makes changes to a file. Any registered event handlers need to be detached whenever the plugin unloads. The safest way to make sure this happens is to use the [[registerEvent|registerEvent()]] method. ```ts import { Plugin } from "obsidian"; export default class ExamplePlugin extends Plugin { async onload() { this.registerEvent('create', () => { console.log('a new file has entered the arena') })); } } ``` ## Timing events If you want to repeatedly call a function with a fixed delay, use the [`window.setInterval()`]( function with the [[registerInterval|registerInterval()]] method. The following example displays the current time in the status bar, updated every second: ```ts import { moment, Plugin } from "obsidian"; export default class ExamplePlugin extends Plugin { statusBar: HTMLElement; async onload() { this.statusBar = this.addStatusBarItem(); this.updateStatusBar(); this.registerInterval( window.setInterval(() => this.updateStatusBar(), 1000) ); } updateStatusBar() { this.statusBar.setText(moment().format("H:mm:ss")); } } ``` > [!tip] Date and time > [Moment]( is a popular JavaScript library for working with dates and time. Obsidian uses Moment internally, so you don't need to install it yourself. You can import it from the Obsidian API instead: > > ```ts > import { moment } from "obsidian"; > ```