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Home / Migrations / Moment.js → Day.js

Moment.js → Day.js

easy

Day.js is a 2KB drop-in replacement for Moment.js (which is deprecated and 70KB). Same API.

Estimated: 1-2h · 5 steps
Progress0%
Step 1: Install Day.js
npm install dayjs && npm uninstall moment
Step 2: Replace imports

Change import moment from 'moment' to import dayjs from 'dayjs'.

find src -name '*.ts*' -exec sed -i "s/import moment from 'moment'/import dayjs from 'dayjs'/g" {} +
Step 3: Replace moment() calls

moment() → dayjs(). Most format/parse/diff methods are identical.

find src -name '*.ts*' -exec sed -i 's/moment(/dayjs(/g' {} +
Step 4: Add plugins for advanced features

Moment features like duration, timezone, relative time require Day.js plugins.

import relativeTime from 'dayjs/plugin/relativeTime'
dayjs.extend(relativeTime)
Step 5: Verify
✓ All date formatting and parsing works correctly

What this migration involves

Moving from Moment.js to Day.js is rated easy and takes about 1-2h on a typical project. The guide breaks it into 5 steps, 4 of which ship with runnable commands and 1 with a verification check.

FAQ

How long does migrating from Moment.js to Day.js take?

Around 1-2h for a typical project — 5 steps, difficulty rated easy, 4 of them with copy-paste commands.

Is moving from Moment.js to Day.js reversible?

No reverse guide is tracked yet, so treat this as a one-way move and keep a full export of your Moment.js data before you start.

What does Day.js cost compared to Moment.js?

Pricing for both tools is contact-based or not tracked yet.