build: date-fns as regular dependency (#2249)

* Make date-fns a regular dependency

* Update localization.mdx

---------

Co-authored-by: Giampaolo Bellavite <io@gpbl.dev>

README.md

@@ -14,12 +14,12 @@ DayPicker is a [React](https://react.dev) component to create date pickers, cale
 - ♿ Complies with WCAG 2.1 AA requirements for accessibility.
 - ⚙️ Customizable internal components for complex use cases.
 
-DayPicker is written in TypeScript and compiled to CommonJS and ESM. It requires [date-fns](https://date-fns.org) as a peer dependency.
+DayPicker is written in TypeScript and compiled to CommonJS and ESM.
 
 ## Installation
 
 ```bash
-npm install react-day-picker date-fns
+npm install react-day-picker
 ```
 
 <a href="https://www.npmjs.com/package/react-day-picker"><img src="https://img.shields.io/npm/v/react-day-picker" alt="npm version"/></a>

package.json

@@ -115,6 +115,9 @@
     "website/docs",
     "tsconfig.json"
   ],
+  "dependencies": {
+    "date-fns": "^3.6.0"
+  },
   "devDependencies": {
     "@date-fns/utc": "^1.2.0",
     "@jest/types": "^29.6.3",
@@ -129,7 +132,6 @@
     "@types/react-dom": "^18.3.0",
     "@typescript-eslint/eslint-plugin": "^7.15.0",
     "@typescript-eslint/parser": "^7.16.0",
-    "date-fns": "^3.6.0",
     "date-fns-jalali": "3.6.0-1",
     "eslint": "^8.57.0",
     "eslint-config-prettier": "^9.1.0",
@@ -156,7 +158,6 @@
     "typescript-css-modules": "^1.0.4"
   },
   "peerDependencies": {
-    "date-fns": "^2.28.0 || ^3.0.0",
     "react": "^18 || ^19"
   },
   "funding": {

website/docs/docs/localization.mdx

@@ -6,7 +6,7 @@ sidebar_position: 5
 
 Learn how to set the locale, adjust the week start day, and apply ISO Week Dates to enhance the user experience across different regions and languages.
 
-## Configure the Locale
+## Locale props
 
 | Prop Name               | Type                                          | Description                                                        |
 | ----------------------- | --------------------------------------------- | ------------------------------------------------------------------ |
@@ -15,6 +15,14 @@ Learn how to set the locale, adjust the week start day, and apply ISO Week Dates
 | `firstWeekContainsDate` | `1` \| `4`                                    | Configure the first date in the first week of the year.            |
 | `ISOWeek`               | `boolean`                                     | Use [ISO Week Dates](https://en.wikipedia.org/wiki/ISO_week_date). |
 
+### Install date-fns
+
+DayPicker uses the [date-fns](https://date-fns.org) library to localize the calendar. To set a different locale, you need to install `date-fns`:
+
+```bash npm2yarn
+npm install date-fns
+```
+
 ### Set a Different Locale
 
 By default, the locale is set to English (US). To localize the calendar, pass a [`Locale`](https://date-fns.org/docs/I18n) object to the `locale` prop.
@@ -31,7 +39,7 @@ import { es } from "date-fns/locale";
   <Examples.Spanish />
 </BrowserWindow>
 
-### First Date of the Week
+## First Date of the Week
 
 Utilize the `weekStartsOn` prop to specify the starting day of the week.
 
@@ -43,7 +51,7 @@ Utilize the `weekStartsOn` prop to specify the starting day of the week.
   <Examples.SpanishWeekStartsOn />
 </BrowserWindow>
 
-### First Week Contains Date
+## First Week Contains Date
 
 The `firstWeekContainsDate` prop can be used to change the first day of the week for the year's initial week, which is used in the calculation of week numbers.
 
@@ -61,7 +69,7 @@ The `firstWeekContainsDate` prop can be used to change the first day of the week
   <Examples.WeeknumberCustom />
 </BrowserWindow>
 
-### ISO Week Dates
+## ISO Week Dates
 
 Use `ISOWeek` to switch using [ISO Week Dates](https://en.wikipedia.org/wiki/ISO_week_date) instead of the locale setting.
 

website/docs/start.mdx

@@ -6,10 +6,10 @@ pagination_next: docs/styling
 
 ## Install the Package
 
-DayPicker is available as `react-day-picker` npm package. It requires [date-fns](https://date-fns.org) as a peer dependency.
+DayPicker is available as `react-day-picker` npm package.
 
 ```bash npm2yarn
-npm install react-day-picker@next date-fns
+npm install react-day-picker@next
 ```
 
 - See #1087 if you are interested in DayPicker supporting different date

website/docs/upgrading.mdx

@@ -19,7 +19,7 @@ Follow these steps to upgrade your project from v8 to v9:
 ### 1. Upgrade to the next version
 
 ```bash npm2yarn
-npm install react-day-picker@next date-fns
+npm install react-day-picker@next
 ```
 
 ### 2. Check for removed props