├── .eslintrc.json
├── src
    ├── app
    │   ├── favicon.ico
    │   ├── page.tsx
    │   ├── example-2-with-supressed-hydration-warning
    │   │   └── page.tsx
    │   ├── example-1-without-supressed-hydration-warning
    │   │   └── page.tsx
    │   ├── example-3-combined
    │   │   └── page.tsx
    │   ├── layout.tsx
    │   └── globals.css
    └── components
    │   └── LocalizedDateTime.tsx
├── next.config.mjs
├── .gitignore
├── package.json
├── public
    ├── vercel.svg
    └── next.svg
├── tsconfig.json
└── README.md


/.eslintrc.json:
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1 | {
2 |   "extends": "next/core-web-vitals"
3 | }
4 | 


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/src/app/favicon.ico:
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https://raw.githubusercontent.com/derweili/nextjs-hydration-issue/main/src/app/favicon.ico


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/next.config.mjs:
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1 | /** @type {import('next').NextConfig} */
2 | const nextConfig = {};
3 | 
4 | export default nextConfig;
5 | 


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/src/app/page.tsx:
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1 | 
2 | export default function Home() {
3 |   return (
4 |     <>
5 |       
6 |     </>
7 |   );
8 | }
9 | 


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/src/app/example-2-with-supressed-hydration-warning/page.tsx:
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 1 | import LocalizedDateTime from '@/components/LocalizedDateTime'
 2 | 
 3 | const PageWithSupressedHydrationWarning = () => {
 4 | 	return (
 5 | 		<>
 6 | 			<h1>Example 2:</h1>
 7 | 			<h2>Localized date <strong>with</strong> supressed hydration warning:</h2>
 8 |       <LocalizedDateTime
 9 |         eventDate="2024-02-01T11:21:00.000Z"
10 |         supressHydrationWarning={true}
11 |         />
12 | 		</>
13 | 	)
14 | }
15 | 
16 | export default PageWithSupressedHydrationWarning


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/src/app/example-1-without-supressed-hydration-warning/page.tsx:
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 1 | import LocalizedDateTime from '@/components/LocalizedDateTime'
 2 | 
 3 | const PageWithoutSupressedHydrationWarning = () => {
 4 | 	return (
 5 | 		<>
 6 | 			<h1>Example 1:</h1>
 7 | 			<h2>Localized date <strong>without</strong> supressed hydration warning:</h2>
 8 |       <LocalizedDateTime
 9 |         eventDate="2024-02-01T11:21:00.000Z"
10 |         supressHydrationWarning={false}
11 |         />
12 | 		</>
13 | 	)
14 | }
15 | 
16 | export default PageWithoutSupressedHydrationWarning


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/.gitignore:
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 1 | # See https://help.github.com/articles/ignoring-files/ for more about ignoring files.
 2 | 
 3 | # dependencies
 4 | /node_modules
 5 | /.pnp
 6 | .pnp.js
 7 | .yarn/install-state.gz
 8 | 
 9 | # testing
10 | /coverage
11 | 
12 | # next.js
13 | /.next/
14 | /out/
15 | 
16 | # production
17 | /build
18 | 
19 | # misc
20 | .DS_Store
21 | *.pem
22 | 
23 | # debug
24 | npm-debug.log*
25 | yarn-debug.log*
26 | yarn-error.log*
27 | 
28 | # local env files
29 | .env*.local
30 | 
31 | # vercel
32 | .vercel
33 | 
34 | # typescript
35 | *.tsbuildinfo
36 | next-env.d.ts
37 | 


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/package.json:
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 1 | {
 2 |   "name": "nextjs-hydration-issue",
 3 |   "version": "0.1.0",
 4 |   "private": true,
 5 |   "scripts": {
 6 |     "dev": "next dev",
 7 |     "build": "next build",
 8 |     "start": "next start",
 9 |     "lint": "next lint"
10 |   },
11 |   "dependencies": {
12 |     "react": "^18",
13 |     "react-dom": "^18",
14 |     "next": "14.1.0"
15 |   },
16 |   "devDependencies": {
17 |     "typescript": "^5",
18 |     "@types/node": "^20",
19 |     "@types/react": "^18",
20 |     "@types/react-dom": "^18",
21 |     "eslint": "^8",
22 |     "eslint-config-next": "14.1.0"
23 |   }
24 | }


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/public/vercel.svg:
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1 | <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 283 64"><path fill="black" d="M141 16c-11 0-19 7-19 18s9 18 20 18c7 0 13-3 16-7l-7-5c-2 3-6 4-9 4-5 0-9-3-10-7h28v-3c0-11-8-18-19-18zm-9 15c1-4 4-7 9-7s8 3 9 7h-18zm117-15c-11 0-19 7-19 18s9 18 20 18c6 0 12-3 16-7l-8-5c-2 3-5 4-8 4-5 0-9-3-11-7h28l1-3c0-11-8-18-19-18zm-10 15c2-4 5-7 10-7s8 3 9 7h-19zm-39 3c0 6 4 10 10 10 4 0 7-2 9-5l8 5c-3 5-9 8-17 8-11 0-19-7-19-18s8-18 19-18c8 0 14 3 17 8l-8 5c-2-3-5-5-9-5-6 0-10 4-10 10zm83-29v46h-9V5h9zM37 0l37 64H0L37 0zm92 5-27 48L74 5h10l18 30 17-30h10zm59 12v10l-3-1c-6 0-10 4-10 10v15h-9V17h9v9c0-5 6-9 13-9z"/></svg>


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/tsconfig.json:
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 1 | {
 2 |   "compilerOptions": {
 3 |     "lib": ["dom", "dom.iterable", "esnext"],
 4 |     "allowJs": true,
 5 |     "skipLibCheck": true,
 6 |     "strict": true,
 7 |     "noEmit": true,
 8 |     "esModuleInterop": true,
 9 |     "module": "esnext",
10 |     "moduleResolution": "bundler",
11 |     "resolveJsonModule": true,
12 |     "isolatedModules": true,
13 |     "jsx": "preserve",
14 |     "incremental": true,
15 |     "plugins": [
16 |       {
17 |         "name": "next"
18 |       }
19 |     ],
20 |     "paths": {
21 |       "@/*": ["./src/*"]
22 |     }
23 |   },
24 |   "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
25 |   "exclude": ["node_modules"]
26 | }
27 | 


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/src/app/example-3-combined/page.tsx:
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 1 | import LocalizedDateTime from '@/components/LocalizedDateTime'
 2 | 
 3 | const PageWithSupressedHydrationWarning = () => {
 4 | 	return (
 5 | 		<>
 6 |       <h1>Example 3 (both combined on one page)</h1>
 7 | 			<h2>Localized date <strong>with</strong> supressed hydration warning:</h2>
 8 |       <LocalizedDateTime
 9 |         eventDate="2024-02-01T11:21:00.000Z"
10 |         supressHydrationWarning={true}
11 |         />
12 | 			<h2>Localized date <strong>without</strong> supressed hydration warning:</h2>
13 |       <LocalizedDateTime
14 |         eventDate="2024-02-01T11:21:00.000Z"
15 |         supressHydrationWarning={false}
16 |         />
17 | 		</>
18 | 	)
19 | }
20 | 
21 | export default PageWithSupressedHydrationWarning


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/src/components/LocalizedDateTime.tsx:
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 1 | 'use client';
 2 | 
 3 | export interface LocalizedDateTimeProps {
 4 | 	eventDate: string;
 5 | 	supressHydrationWarning?: boolean;
 6 | }
 7 | 
 8 | const LocalizedDateTime = ({ eventDate, supressHydrationWarning }: LocalizedDateTimeProps) => {
 9 | 	const localizedDate = new Intl.DateTimeFormat('en-GB', {
10 | 		day: 'numeric',
11 | 		month: 'short',
12 | 		hour: 'numeric',
13 | 		minute: 'numeric',
14 | 		timeZoneName: 'short'
15 | 	}).format(new Date(eventDate));
16 | 
17 | 	// This is always logged to the browser console
18 | 	console.log({localizedDate});
19 | 
20 | 	// When suppressHydrationWarning is used
21 | 	// The server output will never be overwritten
22 | 	// by the browser
23 | 	return (
24 | 		<div suppressHydrationWarning={supressHydrationWarning}>
25 | 			{localizedDate}
26 | 		</div>
27 | 	);
28 | };
29 | 
30 | export default LocalizedDateTime;
31 | 


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/src/app/layout.tsx:
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 1 | import type { Metadata } from "next";
 2 | import "./globals.css";
 3 | 
 4 | export const metadata: Metadata = {
 5 |   title: "Create Next App",
 6 |   description: "Generated by create next app",
 7 | };
 8 | 
 9 | export default function RootLayout({
10 |   children,
11 | }: Readonly<{
12 |   children: React.ReactNode;
13 | }>) {
14 |   return (
15 |     <html lang="en">
16 |       <body>
17 |         <header>
18 |           <nav>
19 |             <ul>
20 |               <li>
21 |                 <a href={'/example-1-without-supressed-hydration-warning'}>
22 |                   Example 1: Without supressed warning
23 |                 </a>
24 |               </li>
25 |               <li>
26 |                 <a href={'/example-2-with-supressed-hydration-warning'}>
27 |                   Example1: With supressed warning
28 |                 </a>
29 |               </li>
30 |               <li>
31 |                 <a href={'/example-3-combined'}>
32 |                   Example 3:
33 |                   Combined
34 |                 </a>
35 |               </li>
36 |             </ul>
37 |           </nav>
38 |         </header>
39 |         <main>
40 |           {children}
41 |         </main>
42 |       </body>
43 |     </html>
44 |   );
45 | }
46 | 


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/public/next.svg:
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1 | <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 394 80"><path fill="#000" d="M262 0h68.5v12.7h-27.2v66.6h-13.6V12.7H262V0ZM149 0v12.7H94v20.4h44.3v12.6H94v21h55v12.6H80.5V0h68.7zm34.3 0h-17.8l63.8 79.4h17.9l-32-39.7 32-39.6h-17.9l-23 28.6-23-28.6zm18.3 56.7-9-11-27.1 33.7h17.8l18.3-22.7z"/><path fill="#000" d="M81 79.3 17 0H0v79.3h13.6V17l50.2 62.3H81Zm252.6-.4c-1 0-1.8-.4-2.5-1s-1.1-1.6-1.1-2.6.3-1.8 1-2.5 1.6-1 2.6-1 1.8.3 2.5 1a3.4 3.4 0 0 1 .6 4.3 3.7 3.7 0 0 1-3 1.8zm23.2-33.5h6v23.3c0 2.1-.4 4-1.3 5.5a9.1 9.1 0 0 1-3.8 3.5c-1.6.8-3.5 1.3-5.7 1.3-2 0-3.7-.4-5.3-1s-2.8-1.8-3.7-3.2c-.9-1.3-1.4-3-1.4-5h6c.1.8.3 1.6.7 2.2s1 1.2 1.6 1.5c.7.4 1.5.5 2.4.5 1 0 1.8-.2 2.4-.6a4 4 0 0 0 1.6-1.8c.3-.8.5-1.8.5-3V45.5zm30.9 9.1a4.4 4.4 0 0 0-2-3.3 7.5 7.5 0 0 0-4.3-1.1c-1.3 0-2.4.2-3.3.5-.9.4-1.6 1-2 1.6a3.5 3.5 0 0 0-.3 4c.3.5.7.9 1.3 1.2l1.8 1 2 .5 3.2.8c1.3.3 2.5.7 3.7 1.2a13 13 0 0 1 3.2 1.8 8.1 8.1 0 0 1 3 6.5c0 2-.5 3.7-1.5 5.1a10 10 0 0 1-4.4 3.5c-1.8.8-4.1 1.2-6.8 1.2-2.6 0-4.9-.4-6.8-1.2-2-.8-3.4-2-4.5-3.5a10 10 0 0 1-1.7-5.6h6a5 5 0 0 0 3.5 4.6c1 .4 2.2.6 3.4.6 1.3 0 2.5-.2 3.5-.6 1-.4 1.8-1 2.4-1.7a4 4 0 0 0 .8-2.4c0-.9-.2-1.6-.7-2.2a11 11 0 0 0-2.1-1.4l-3.2-1-3.8-1c-2.8-.7-5-1.7-6.6-3.2a7.2 7.2 0 0 1-2.4-5.7 8 8 0 0 1 1.7-5 10 10 0 0 1 4.3-3.5c2-.8 4-1.2 6.4-1.2 2.3 0 4.4.4 6.2 1.2 1.8.8 3.2 2 4.3 3.4 1 1.4 1.5 3 1.5 5h-5.8z"/></svg>


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/README.md:
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 1 | This is a [Next.js](https://nextjs.org/) project bootstrapped with [`create-next-app`](https://github.com/vercel/next.js/tree/canary/packages/create-next-app).
 2 | 
 3 | ## Getting Started
 4 | 
 5 | First, run the development server:
 6 | 
 7 | ```bash
 8 | npm run dev
 9 | # or
10 | yarn dev
11 | # or
12 | pnpm dev
13 | # or
14 | bun dev
15 | ```
16 | 
17 | Open [http://localhost:3000](http://localhost:3000) with your browser to see the result.
18 | 
19 | You can start editing the page by modifying `app/page.tsx`. The page auto-updates as you edit the file.
20 | 
21 | This project uses [`next/font`](https://nextjs.org/docs/basic-features/font-optimization) to automatically optimize and load Inter, a custom Google Font.
22 | 
23 | ## Learn More
24 | 
25 | To learn more about Next.js, take a look at the following resources:
26 | 
27 | - [Next.js Documentation](https://nextjs.org/docs) - learn about Next.js features and API.
28 | - [Learn Next.js](https://nextjs.org/learn) - an interactive Next.js tutorial.
29 | 
30 | You can check out [the Next.js GitHub repository](https://github.com/vercel/next.js/) - your feedback and contributions are welcome!
31 | 
32 | ## Deploy on Vercel
33 | 
34 | The easiest way to deploy your Next.js app is to use the [Vercel Platform](https://vercel.com/new?utm_medium=default-template&filter=next.js&utm_source=create-next-app&utm_campaign=create-next-app-readme) from the creators of Next.js.
35 | 
36 | Check out our [Next.js deployment documentation](https://nextjs.org/docs/deployment) for more details.
37 | 


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/src/app/globals.css:
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 1 | :root {
 2 |   --max-width: 1100px;
 3 |   --border-radius: 12px;
 4 |   --font-mono: ui-monospace, Menlo, Monaco, "Cascadia Mono", "Segoe UI Mono",
 5 |     "Roboto Mono", "Oxygen Mono", "Ubuntu Monospace", "Source Code Pro",
 6 |     "Fira Mono", "Droid Sans Mono", "Courier New", monospace;
 7 | 
 8 |   --foreground-rgb: 0, 0, 0;
 9 |   --background-start-rgb: 214, 219, 220;
10 |   --background-end-rgb: 255, 255, 255;
11 | }
12 | 
13 | * {
14 |   box-sizing: border-box;
15 |   padding: 0;
16 |   margin: 0;
17 | }
18 | 
19 | html,
20 | body {
21 |   max-width: 100vw;
22 |   overflow-x: hidden;
23 | }
24 | 
25 | body {
26 |   color: rgb(var(--foreground-rgb));
27 |   background-image: linear-gradient(
28 |       to bottom,
29 |       transparent,
30 |       rgb(var(--background-end-rgb))
31 |     );
32 |   background-color: rgb(var(--background-start-rgb));
33 |   background-size: cover;
34 |   min-height: 100vh;
35 |   font-family: --apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
36 |     Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
37 | }
38 | 
39 | a {
40 |   color: inherit;
41 |   text-decoration: none;
42 | }
43 | 
44 | 
45 | nav ul {
46 |   display: flex;
47 |   justify-content: center;
48 |   list-style: none;
49 |   margin: 1rem;
50 |   gap: 20px;
51 | }
52 | 
53 | nav li a {
54 |   border: 1px solid #444;
55 |   padding: 0.5rem 1rem;
56 |   border-radius: 4px;
57 | }
58 | 
59 | nav li a:hover {
60 |   background-color: #444;
61 |   color: white;
62 | }
63 | 
64 | main {
65 |   max-width: var(--max-width);
66 |   margin: 0 auto;
67 |   padding: 2rem;
68 | }


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