Can't import dayjs on dev server

Edit: Fixed by specifically importing the the ES module

import dayjs from "dayjs/esm";
import relativeTime from "dayjs/esm/plugin/relativeTime";

Original bug report

Describe the bug We have a basic component that imports dayjs, but there is an error displaying a page with this component when using npm run dev. Running in production with npm run build && npm start works fine.

The component:

<script>
	import dayjs from 'dayjs';
	const date = dayjs().format('YYYY-MM-DD');
</script>

<header>
	<div>
	    <time datetime="{date}">
                 {date}
            </time>
	</div>
</header>

Logs Browser logs

500
__vite_ssr_import_1__.default is not a function

TypeError: __vite_ssr_import_1__.default is not a function
    at HeaderTop.svelte:3:22
    at Object.$$render (/Users/stanislav.khromov/Documents/GitHub/kratos-svelte/node_modules/svelte/internal/index.js:1369:22)
    at eval (/Users/stanislav.khromov/Documents/GitHub/kratos-svelte/src/routes/index.svelte:15:103)
    at Object.$$render (/Users/stanislav.khromov/Documents/GitHub/kratos-svelte/node_modules/svelte/internal/index.js:1369:22)
    at Object.default (root.svelte:46:46)
    at eval (/Users/stanislav.khromov/Documents/GitHub/kratos-svelte/src/routes/$layout.svelte:11:41)
    at Object.$$render (/Users/stanislav.khromov/Documents/GitHub/kratos-svelte/node_modules/svelte/internal/index.js:1369:22)
    at root.svelte:42:13
    at $$render (/Users/stanislav.khromov/Documents/GitHub/kratos-svelte/node_modules/svelte/internal/index.js:1369:22)
    at Object.render (/Users/stanislav.khromov/Documents/GitHub/kratos-svelte/node_modules/svelte/internal/index.js:1377:26)

To Reproduce ✅ Please make sure you’ve tested with the latest versions of Svelte and SvelteKit.

Information about your SvelteKit Installation:

• The output of npx envinfo --system --npmPackages svelte,@sveltejs/kit --binaries --browsers

  System:
    OS: macOS 10.15.7
    CPU: (16) x64 Intel(R) Core(TM) i9-9980HK CPU @ 2.40GHz
    Memory: 1.86 GB / 32.00 GB
    Shell: 5.7.1 - /bin/zsh
  Binaries:
    Node: 15.12.0 - ~/.nvm/versions/node/v15.12.0/bin/node
    npm: 7.6.3 - ~/.nvm/versions/node/v15.12.0/bin/npm
  Browsers:
    Chrome: 89.0.4389.90
    Firefox: 86.0.1
    Safari: 14.0.3
  npmPackages:
    @sveltejs/kit: next => 1.0.0-next.61 
    svelte: ^3.29.0 => 3.35.0 

• Your browser Chrome 89

• Your adapter (e.g. Node, static, Vercel, Begin, etc…) Node

Severity Blocking SvelteKit usage.

Additional context Add any other context about the problem here.

[eikaramba]

same error here too. Cannot use import statement outside a module

import dayjs from 'dayjs/esm/index.js'
import isToday from 'dayjs/esm/plugin/isToday/index.js'
import isYesterday from 'dayjs/esm/plugin/isYesterday/index.js'

Happens upon npm run build

Strangely enough, when i change everything back and add the .js extension:

import dayjs from 'dayjs'
import isToday from 'dayjs/plugin/isToday.js'
import isYesterday from 'dayjs/plugin/isYesterday.js'

it works

[NoelJacob]

@khromov I still get the error. I did not change anything else, just added the import dayjs from "dayjs/esm"

On pnpm run dev:

> windinew@0.0.1 dev C:\Users\HP\Desktop\windinew
> svelte-kit dev

> Listening on http://localhost:3000
4:03:13 pm [vite] Error when evaluating SSR module C:\Users\HP\Desktop\windinew\src\routes\index.svelte:
C:\Users\HP\Desktop\windinew\node_modules\.pnpm\dayjs@1.10.4\node_modules\dayjs\esm\index.js:1
import * as C from './constant';
^^^^^^

SyntaxError: Cannot use import statement outside a module
    at wrapSafe (node:internal/modules/cjs/loader:1024:16)
    at Module._compile (node:internal/modules/cjs/loader:1072:27)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1137:10)
    at Module.load (node:internal/modules/cjs/loader:973:32)
    at Function.Module._load (node:internal/modules/cjs/loader:813:14)
    at Module.require (node:internal/modules/cjs/loader:997:19)
    at require (node:internal/modules/cjs/helpers:92:18)
    at nodeRequire (C:\Users\HP\Desktop\windinew\node_modules\.pnpm\vite@2.1.3\node_modules\vite\dist\node\chunks\dep-0776dd57.js:68933:17)
    at ssrImport (C:\Users\HP\Desktop\windinew\node_modules\.pnpm\vite@2.1.3\node_modules\vite\dist\node\chunks\dep-0776dd57.js:68891:20)
    at eval (C:\Users\HP\Desktop\windinew\src\routes\index.svelte:7:31)
 ERROR  Command failed with exit code 1.