[HOLD for payment 2023-11-22] [Feature request] Replace the moment library with some lightweight date utility library

[mountiny]

### Problem

Coming from this Slack thread and Callstack proposal.

The moment library is a powerful library but has performance disadvantages that comes from its OOP design. This design makes it fail working with tree-shaking, so it’s bundle size it’s huge (especially with internalisation or timezone support enabled) - this impacts mostly the web version of Expensify app.

Moreover, the moment library is now a “legacy project in maintenance mode” so it is not actively developed anymore.

More about above here: https://momentjs.com/docs/#/-project-status/

Solution

There are some other powerful yet lightweight date libraries like day.js (the most lightweight) or date-fns (supports tree-shaking) that could successfully replace the moment library in our app. My personal preference is date-fns because of its support for tree-shaking and wider popularity among community, but using day.js may be easier from the Expensify codebase perspective because of its API that is quite similar to the moment one (e.g. parsing date strings using constructor or day/month/year getters etc. - please check the link I’ve posted below for more details).

Context/Examples/Screenshots/Notes: More about the subject, containing the comparison of the most popular moment replacements can be found here: https://github.com/you-dont-need/You-Dont-Need-Momentjs/blob/master/README.md

• Add an eslint rule once we are done which will prohibit adding the library back

[melvin-bot]

Triggered auto assignment to @anmurali (NewFeature), see https://stackoverflowteams.com/c/expensify/questions/14418#:~:text=BugZero%20process%20steps%20for%20feature%20requests for more details.

[mountiny]

No need to action here now Anu, Callstack will work on this

[burczu]

Hey! It's Bartek from Callstack - expert contributor group - I'll be working on this one.

[mountiny]

Thanks, please, first post a plan of how to exectute this migration before you go ahead.

[mountiny]

@burczu would you be bale to share a plan for this project and some ETA, thanks!

[burczu]

Hey @mountiny! Sorry for being silent in this issue - I'm 100% involved in the Secure Logins issue (migration to use accountID's instead of emails in personal details) right now and had no time for anything else. I'll do my best to share some plan for this issue today or on Monday.