Property 'duration' does not exist on type 'typeof dayjs'.

**Describe the bug**
I was trying to migrate from moment to dayjs. I have monorepo setup along with typescript. For the reusability, i was trying to move dayjs with necessary extends inside a util library inside nx which looks something like this -

```
import dayjs from 'dayjs/esm';
import duration from 'dayjs/esm/plugin/duration';
import isBetween from 'dayjs/esm/plugin/isBetween';
import isSameOrAfter from 'dayjs/esm/plugin/isSameOrAfter';
import isSameOrBefore from 'dayjs/esm/plugin/isSameOrBefore';
import timezone from 'dayjs/esm/plugin/timezone';
import utc from 'dayjs/esm/plugin/utc';

dayjs.extend(isBetween);
dayjs.extend(utc);
dayjs.extend(timezone);
dayjs.extend(duration);
dayjs.extend(isSameOrAfter);
dayjs.extend(isSameOrBefore);

export const dayjsExt = dayjs;
```

I don't want to enable `allowSyntheticDefaultImports` and `esModuleInterop` so I have added a patch -

```
diff --git a/node_modules/dayjs/esm/index.d.ts b/node_modules/dayjs/esm/index.d.ts
index cd159dc..46c227a 100644
--- a/node_modules/dayjs/esm/index.d.ts
+++ b/node_modules/dayjs/esm/index.d.ts
@@ -1,6 +1,6 @@
///

-export = dayjs;
+export default dayjs;

declare function dayjs (date?: dayjs.ConfigType): dayjs.Dayjs

diff --git a/node_modules/dayjs/esm/index.js b/node_modules/dayjs/esm/index.js
index a82986b..fce6b4d 100644
--- a/node_modules/dayjs/esm/index.js
+++ b/node_modules/dayjs/esm/index.js
@@ -1,6 +1,6 @@
-import * as C from './constant';
-import en from './locale/en';
-import U from './utils';
+import * as C from './constant.js';
+import en from './locale/en.js';
+import U from './utils.js';
var L = 'en'; // global locale

var Ls = {}; // global loaded locale
diff --git a/node_modules/dayjs/esm/plugin/duration/index.d.ts b/node_modules/dayjs/esm/plugin/duration/index.d.ts
index dc974a5..05ee1cc 100644
--- a/node_modules/dayjs/esm/plugin/duration/index.d.ts
+++ b/node_modules/dayjs/esm/plugin/duration/index.d.ts
@@ -3,7 +3,7 @@ import { OpUnitType, UnitTypeLongPlural } from 'dayjs/esm';

declare const plugin: PluginFunc
export as namespace plugin;
-export = plugin
+export default plugin

declare namespace plugin {
/**
diff --git a/node_modules/dayjs/esm/plugin/duration/index.js b/node_modules/dayjs/esm/plugin/duration/index.js
index a241d4b..ee2cdd1 100644
--- a/node_modules/dayjs/esm/plugin/duration/index.js
+++ b/node_modules/dayjs/esm/plugin/duration/index.js
@@ -1,4 +1,4 @@
-import { MILLISECONDS_A_DAY, MILLISECONDS_A_HOUR, MILLISECONDS_A_MINUTE, MILLISECONDS_A_SECOND, MILLISECONDS_A_WEEK, REGEX_FORMAT } from '../../constant';
+import { MILLISECONDS_A_DAY, MILLISECONDS_A_HOUR, MILLISECONDS_A_MINUTE, MILLISECONDS_A_SECOND, MILLISECONDS_A_WEEK, REGEX_FORMAT } from '../../constant.js';
var MILLISECONDS_A_YEAR = MILLISECONDS_A_DAY * 365;
var MILLISECONDS_A_MONTH = MILLISECONDS_A_YEAR / 12;
var durationRegex = /^(-|\+)?P(?:([-+]?[0-9,.]*)Y)?(?:([-+]?[0-9,.]*)M)?(?:([-+]?[0-9,.]*)W)?(?:([-+]?[0-9,.]*)D)?(?:T(?:([-+]?[0-9,.]*)H)?(?:([-+]?[0-9,.]*)M)?(?:([-+]?[0-9,.]*)S)?)?$/;
diff --git a/node_modules/dayjs/esm/plugin/isBetween/index.d.ts b/node_modules/dayjs/esm/plugin/isBetween/index.d.ts
index 1c62711..e4761fd 100644
--- a/node_modules/dayjs/esm/plugin/isBetween/index.d.ts
+++ b/node_modules/dayjs/esm/plugin/isBetween/index.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType, OpUnitType } from 'dayjs/esm'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs/esm' {
interface Dayjs {
diff --git a/node_modules/dayjs/esm/plugin/isSameOrAfter/index.d.ts b/node_modules/dayjs/esm/plugin/isSameOrAfter/index.d.ts
index 7b6d239..c16bde4 100644
--- a/node_modules/dayjs/esm/plugin/isSameOrAfter/index.d.ts
+++ b/node_modules/dayjs/esm/plugin/isSameOrAfter/index.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType, OpUnitType } from 'dayjs/esm'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs/esm' {
interface Dayjs {
diff --git a/node_modules/dayjs/esm/plugin/isSameOrBefore/index.d.ts b/node_modules/dayjs/esm/plugin/isSameOrBefore/index.d.ts
index 7ec009f..3c35df3 100644
--- a/node_modules/dayjs/esm/plugin/isSameOrBefore/index.d.ts
+++ b/node_modules/dayjs/esm/plugin/isSameOrBefore/index.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType, OpUnitType } from 'dayjs/esm'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs/esm' {
interface Dayjs {
diff --git a/node_modules/dayjs/esm/plugin/timezone/index.d.ts b/node_modules/dayjs/esm/plugin/timezone/index.d.ts
index 5a2d9f2..d618a7a 100644
--- a/node_modules/dayjs/esm/plugin/timezone/index.d.ts
+++ b/node_modules/dayjs/esm/plugin/timezone/index.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType } from 'dayjs/esm'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs/esm' {
interface Dayjs {
diff --git a/node_modules/dayjs/esm/plugin/timezone/index.js b/node_modules/dayjs/esm/plugin/timezone/index.js
index 2f63de2..5f0e435 100644
--- a/node_modules/dayjs/esm/plugin/timezone/index.js
+++ b/node_modules/dayjs/esm/plugin/timezone/index.js
@@ -1,4 +1,4 @@
-import { MIN, MS } from '../../constant';
+import { MIN, MS } from '../../constant.js';
var typeToPos = {
year: 0,
month: 1,
diff --git a/node_modules/dayjs/esm/plugin/utc/index.d.ts b/node_modules/dayjs/esm/plugin/utc/index.d.ts
index 15c61fe..04a2d14 100644
--- a/node_modules/dayjs/esm/plugin/utc/index.d.ts
+++ b/node_modules/dayjs/esm/plugin/utc/index.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType } from 'dayjs/esm'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs/esm' {
interface Dayjs {
diff --git a/node_modules/dayjs/esm/plugin/utc/index.js b/node_modules/dayjs/esm/plugin/utc/index.js
index a8a05f5..552551e 100644
--- a/node_modules/dayjs/esm/plugin/utc/index.js
+++ b/node_modules/dayjs/esm/plugin/utc/index.js
@@ -1,4 +1,4 @@
-import { MILLISECONDS_A_MINUTE, MIN } from '../../constant';
+import { MILLISECONDS_A_MINUTE, MIN } from '../../constant.js';
var REGEX_VALID_OFFSET_FORMAT = /[+-]\d\d(?::?\d\d)?/g;
var REGEX_OFFSET_HOURS_MINUTES_FORMAT = /([+-]|\d\d)/g;

diff --git a/node_modules/dayjs/esm/utils.js b/node_modules/dayjs/esm/utils.js
index b5a8131..7df153a 100644
--- a/node_modules/dayjs/esm/utils.js
+++ b/node_modules/dayjs/esm/utils.js
@@ -1,4 +1,4 @@
-import * as C from './constant';
+import * as C from './constant.js';

var padStart = function padStart(string, length, pad) {
var s = String(string);
diff --git a/node_modules/dayjs/package.json b/node_modules/dayjs/package.json
index d3e7c31..aaa63a0 100644
--- a/node_modules/dayjs/package.json
+++ b/node_modules/dayjs/package.json
@@ -1,8 +1,9 @@
{
"name": "dayjs",
+ "type": "module",
"version": "1.11.13",
"description": "2KB immutable date time library alternative to Moment.js with the same modern API ",
- "main": "dayjs.min.js",
+ "main": "esm/index.js",
"types": "index.d.ts",
"scripts": {
"test": "TZ=Pacific/Auckland npm run test-tz && TZ=Europe/London npm run test-tz && TZ=America/Whitehorse npm run test-tz && npm run test-tz && jest",
diff --git a/node_modules/dayjs/plugin/duration.d.ts b/node_modules/dayjs/plugin/duration.d.ts
index 9675a80..7c03040 100644
--- a/node_modules/dayjs/plugin/duration.d.ts
+++ b/node_modules/dayjs/plugin/duration.d.ts
@@ -3,7 +3,7 @@ import { OpUnitType, UnitTypeLongPlural } from 'dayjs';

declare const plugin: PluginFunc
export as namespace plugin;
-export = plugin
+export default plugin

declare namespace plugin {
/**
diff --git a/node_modules/dayjs/plugin/isBetween.d.ts b/node_modules/dayjs/plugin/isBetween.d.ts
index 431fff8..94388bf 100644
--- a/node_modules/dayjs/plugin/isBetween.d.ts
+++ b/node_modules/dayjs/plugin/isBetween.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType, OpUnitType } from 'dayjs'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs' {
interface Dayjs {
diff --git a/node_modules/dayjs/plugin/isSameOrAfter.d.ts b/node_modules/dayjs/plugin/isSameOrAfter.d.ts
index 916bc80..8edcf3d 100644
--- a/node_modules/dayjs/plugin/isSameOrAfter.d.ts
+++ b/node_modules/dayjs/plugin/isSameOrAfter.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType, OpUnitType } from 'dayjs'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs' {
interface Dayjs {
diff --git a/node_modules/dayjs/plugin/isSameOrBefore.d.ts b/node_modules/dayjs/plugin/isSameOrBefore.d.ts
index d52b095..8b64a12 100644
--- a/node_modules/dayjs/plugin/isSameOrBefore.d.ts
+++ b/node_modules/dayjs/plugin/isSameOrBefore.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType, OpUnitType } from 'dayjs'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs' {
interface Dayjs {
diff --git a/node_modules/dayjs/plugin/timezone.d.ts b/node_modules/dayjs/plugin/timezone.d.ts
index 049bb08..19b21bf 100644
--- a/node_modules/dayjs/plugin/timezone.d.ts
+++ b/node_modules/dayjs/plugin/timezone.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType } from 'dayjs'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs' {
interface Dayjs {
diff --git a/node_modules/dayjs/plugin/utc.d.ts b/node_modules/dayjs/plugin/utc.d.ts
index 544ea4e..be9d1f4 100644
--- a/node_modules/dayjs/plugin/utc.d.ts
+++ b/node_modules/dayjs/plugin/utc.d.ts
@@ -1,7 +1,7 @@
import { PluginFunc, ConfigType } from 'dayjs'

declare const plugin: PluginFunc
-export = plugin
+export default plugin

declare module 'dayjs' {
interface Dayjs {
```

**Expected behavior**
On usage files, if I try to use `dayjsExt.duration` or even in the same file, I am getting `Property 'duration' does not exist on type 'typeof dayjs'. ` which should not be the case.

**Information**
- Day.js Version 1.11.13
- OS: macOS
- Browser Chrome 128.0.6613.84
- Time zone: GMT+05:30 IST (Indian Standard Time)

Start by reproducing the TypeScript error from the shown Nx utility imports, then inspect node_modules/dayjs/esm/index.d.ts and node_modules/dayjs/esm/plugin/duration/index.d.ts alongside the usage file. Done means the documented ESM/plugin setup exposes duration and the other extended APIs without requiring the reported local patches.

Written by the indexing model from the issue text.