Best Date/Time Libraries in 2025: date-fns vs Day.js vs Temporal API

Date Handling is Hard

JavaScript's Date object is notoriously problematic. Modern libraries provide better APIs, timezone handling, and immutability.

Quick Comparison

date-fns: Functional Approach

date-fns provides functional, tree-shakeable date utilities.

Key Features

• Tree-shakeable - import only what you need
• Immutable - never mutates dates
• Comprehensive - 200+ functions
• TypeScript - excellent types

Example

```typescript import { format, addDays, isAfter } from 'date-fns';

const today = new Date(); const nextWeek = addDays(today, 7);

console.log(format(nextWeek, 'MMMM do, yyyy')); console.log(isAfter(nextWeek, today)); // true ```

Best For

• Bundle-size conscious apps
• Functional programming style
• Most date operations

Day.js: Moment.js Replacement

Day.js is a lightweight Moment.js alternative with the same API.

Key Features

• 2kb - tiny bundle
• Moment API - familiar syntax
• Plugins - extend functionality
• Immutable - safe operations

Example

```typescript import dayjs from 'dayjs'; import relativeTime from 'dayjs/plugin/relativeTime';

dayjs.extend(relativeTime);

const date = dayjs('2024-01-15'); console.log(date.format('MMMM D, YYYY')); console.log(date.fromNow()); // "2 months ago" ```

Best For

• Moment.js migration
• Simple date formatting
• Minimal bundle impact

Luxon: Full-Featured

Luxon provides comprehensive date/time handling with built-in timezone support.

Key Features

• Timezone native - no plugins needed
• Intl-based - uses browser APIs
• Duration/Interval - time spans
• ISO 8601 - full support

Example

```typescript import { DateTime } from 'luxon';

const dt = DateTime.now().setZone('America/New_York'); console.log(dt.toLocaleString(DateTime.DATETIME_FULL));

const tokyo = dt.setZone('Asia/Tokyo'); console.log(tokyo.toISO()); ```

Best For

• Timezone-heavy applications
• International apps
• Complex date math

Temporal API (Coming Soon)

Temporal is the future native JavaScript date API.

Key Features

• Native - no library needed
• Immutable - by design
• Timezone-aware - built-in
• Precise - nanosecond support

Example (Stage 3 Proposal)

```typescript const now = Temporal.Now.zonedDateTimeISO(); const tokyo = now.withTimeZone('Asia/Tokyo'); const nextMonth = now.add({ months: 1 }); ```

Best For

• Future-proofing
• When browser support arrives

Our Recommendation

• Most projects: date-fns
• Minimal bundle: Day.js
• Timezone-heavy: Luxon
• Future: Watch Temporal API

Explore utility libraries in our Tools directory or compare options with our Compare tool.

Sources

• date-fns Documentation
• Day.js Documentation
• Luxon Documentation
• Temporal Proposal