What it is

The two live replacements for the deprecated Moment.js. date-fns (v4) is a tree-shakeable set of pure functions with first-class time-zone support. Day.js is a 2KB immutable wrapper with a Moment-compatible API and optional plugins.

Why it earns a slot

Relative timestamps, date maths and time zones are where hand-written code quietly breaks across DST and locales. Pick date-fns for tree-shaking, Day.js for the smallest bundle or a Moment port.

Know before you commit

Never install Moment.js — it is in maintenance mode and ships huge locale files. The native Temporal API is arriving but is not yet safe to rely on everywhere.

Getting started

npm install date-fns

Field notes

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Pricing snapshot

Free · MIT

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Drop into your Lovable chat

Evaluate date-fns + Day.js (https://date-fns.org) for this project, then use it only if it fits what we are already building.
Context: Date formatting. The two live replacements for the deprecated Moment.js. date-fns (v4) is a tree-shakeable set of pure functions with first-class time-zone support. Day.js is a 2KB immutable wrapper with a Moment-compatible API and optional plugins.
Reviewer notes (general, not written for this codebase): Relative timestamps, date maths and time zones are where hand-written code quietly breaks across DST and locales. Pick date-fns for tree-shaking, Day.js for the smallest bundle or a Moment port.
Watch out for: Never install Moment.js — it is in maintenance mode and ships huge locale files. The native Temporal API is arriving but is not yet safe to rely on everywhere.
Pricing: Free · MIT
Setup: npm install date-fns
Rules: treat the notes above as background only. Do not assume a theme, style, layout or feature that is not already in this project — inspect the existing code first and ask me before changing visual direction.

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