@cubejs-client/core "internalDayjs" config affects all dayjs imports

[benskz]

Describe the bug
While packages/cubejs-client-core/src/time.tstries to customize an internal dayjs instance, these options are also applied to the default dayjs instance.

To Reproduce

import dayjs from 'dayjs';
import { internalDayjs } from '@cubejs-client/core'

console.log(dayjs().startOf('week').format('dddd'); // Sunday

const cubeDayjs = internalDayjs(); // sets weekStart to 1

console.log(dayjs().startOf('week').format('dddd'); // Monday

Expected behavior
Cube Client's dayjs internal instance options should not be reflected in the default dayjs instance.

Version:
"@cubejs-client/core": "^1.5.4",

[igorlukanin]

Thanks for reporting this @benskz!

Looks like dayjs has a fundamental design limitation - there's no way to extend only a specific instance. The dayjs.extend() method modifies the global prototype. Looks like a migration of the @cubejs-client/core package to date-fns or Temporal API is the only solution to this.

Conversation with Claude: claude.txt

[github-actions]

If you are interested in working on this issue, please go ahead and provide PR for that.
We'd be happy to review it and merge it.
If this is the first time you are contributing a Pull Request to Cube, please check our contribution guidelines.
You can also post any questions while contributing in the #contributors channel in the Cube Slack.

[mystichronicle]

@igorlukanin Could you please review the attached PR ?