Kairos

A lightweight, zero-dependency JavaScript library for date and time manipulation with a powerful plugin architecture, comprehensive holiday support for 10+ locales, and business day calculations.

🌟 Key Features

🎉 Advanced Holiday System

• 10+ Locales with built-in holiday support:
  • 🇺🇸 United States - Federal holidays + 50 state holidays
  • 🇩🇪 Germany - National + 16 Länder holidays
  • 🇫🇷 France - National + regional holidays
  • 🇪🇸 Spain - National + autonomous communities
  • 🇮🇹 Italy - National + regional observances
  • 🇧🇷 Brazil - Federal + state holidays
  • 🇷🇺 Russia - Federal + regional holidays
  • 🇨🇳 China - Traditional lunar + modern holidays
  • 🇯🇵 Japan - National + Golden Week holidays
  • 🇹🇷 Turkey - National + religious holidays
• Dynamic Holiday Calculation - Easter-based, lunar calendar, nth weekday rules
• Regional Holidays - State/province specific holidays
• Business Day Calculations - Holiday-aware business day operations
• Custom Holiday Rules - Define your own holiday calculation logic

🚀 Core Features

• Zero Dependencies - Completely self-contained with no external requirements
• Plugin Architecture - Load only what you need, tree-shaking friendly
• Immutable API - All operations return new instances
• TypeScript Support - Full type definitions included
• Cross-Platform - Works in Node.js 14+ and modern browsers
• Lightweight - Core ~25KB, all plugins ~190KB minified + gzipped
• Comprehensive Testing - 95%+ code coverage with 400+ tests

Quick Start

npm install @oxog/kairos

const kairos = require('@oxog/kairos');
const holidayEngine = require('@oxog/kairos/plugins/holiday/engine');
const localeUS = require('@oxog/kairos/plugins/locale/en-US');

// Setup with holiday support
kairos.use([holidayEngine, localeUS]);

// Current date/time
const now = kairos();

// Parse dates
const date = kairos('2024-12-25');

// Format dates
console.log(date.format('MMMM D, YYYY')); // December 25, 2024

// Check holidays
console.log(date.isHoliday()); // true
console.log(date.getHolidayName()); // "Christmas Day"

// Date arithmetic
const tomorrow = date.add(1, 'day');
const lastWeek = date.subtract(1, 'week');

// Comparisons
console.log(date.isBefore(tomorrow)); // true
console.log(date.isAfter(lastWeek)); // true

Core API

Creating Instances

kairos(); // Current date/time
kairos('2024-06-15'); // ISO string
kairos(1718460600000); // Unix timestamp (ms)
kairos([2024, 5, 15]); // Array [year, month, day]
kairos({ year: 2024, month: 6 }); // Object

Manipulation

const date = kairos('2024-06-15');

date.add(1, 'day'); // Add time
date.subtract(2, 'hours'); // Subtract time
date.startOf('month'); // Beginning of month
date.endOf('year'); // End of year
date.clone(); // Create copy

Comparison

const date1 = kairos('2024-06-15');
const date2 = kairos('2024-06-20');

date1.isBefore(date2); // true
date1.isAfter(date2); // false
date1.isSame(date2, 'month'); // true
date1.isBetween(start, end); // Check if between
date1.diff(date2, 'days'); // -5

Display

const date = kairos('2024-06-15 14:30:00');

date.format('YYYY-MM-DD'); // 2024-06-15
date.format('MMM D, YYYY h:mm A'); // Jun 15, 2024 2:30 PM
date.toISOString(); // 2024-06-15T14:30:00.000Z
date.valueOf(); // Unix timestamp (ms)
date.toDate(); // JavaScript Date object

Plugins

🎊 Holiday Support & Business Days

const holidayEngine = require('@oxog/kairos/plugins/holiday/engine');
const businessPlugin = require('@oxog/kairos/plugins/business/workday');
const localeUS = require('@oxog/kairos/plugins/locale/en-US');
const localeFR = require('@oxog/kairos/plugins/locale/fr-FR');

kairos.use([holidayEngine, businessPlugin, localeUS, localeFR]);

// Check holidays
const christmas = kairos('2024-12-25');
christmas.isHoliday(); // true
christmas.getHolidayName(); // "Christmas Day"

// Get holidays for a year
const holidays2024 = kairos.getHolidays(2024);
// Returns array of holiday dates with names

// Business days with holiday awareness
const date = kairos('2024-12-24');
date.isBusinessDay(); // false (Christmas Eve)
date.nextBusinessDay(); // Skips holidays & weekends
date.addBusinessDays(5); // Holiday-aware calculation

// Locale-specific holidays
kairos.locale('fr-FR');
const bastilleDay = kairos('2024-07-14');
bastilleDay.isHoliday(); // true (Fête Nationale)

// Regional holidays
const spanishHolidays = kairos.getSpanishHolidays('cataluna');
// Returns Catalonia-specific holidays

Duration

const durationPlugin = require('@oxog/kairos/plugins/duration/duration');
kairos.use(durationPlugin);

const duration = kairos.duration({ hours: 2, minutes: 30 });
duration.asMinutes(); // 150
duration.humanize(); // "3 hours"
duration.toISOString(); // "PT2H30M"

Range

const rangePlugin = require('@oxog/kairos/plugins/range/range');
kairos.use(rangePlugin);

const range = kairos.range(start, end);
range.contains(date); // Check if date in range
range.overlaps(otherRange); // Check overlap
range.duration(); // Get duration

Relative Time

const relativePlugin = require('@oxog/kairos/plugins/relative/relative');
kairos.use(relativePlugin);

const past = kairos().subtract(2, 'hours');
past.fromNow(); // "2 hours ago"
past.from(reference); // Relative to reference
past.calendar(); // "Today at 2:30 PM"

Timezone

const timezonePlugin = require('@oxog/kairos/plugins/timezone/timezone');
kairos.use(timezonePlugin);

const local = kairos();
const utc = local.utc(); // Convert to UTC
utc.local(); // Back to local
local.utcOffset(); // Offset in minutes

🌍 Localization (10 Languages)

// Available locales with comprehensive holiday support
const localeUS = require('@oxog/kairos/plugins/locale/en-US'); // 🇺🇸 United States
const localeUK = require('@oxog/kairos/plugins/locale/en-GB'); // 🇬🇧 United Kingdom
const localeDE = require('@oxog/kairos/plugins/locale/de-DE'); // 🇩🇪 Germany
const localeFR = require('@oxog/kairos/plugins/locale/fr-FR'); // 🇫🇷 France
const localeES = require('@oxog/kairos/plugins/locale/es-ES'); // 🇪🇸 Spain
const localeIT = require('@oxog/kairos/plugins/locale/it-IT'); // 🇮🇹 Italy
const localePT = require('@oxog/kairos/plugins/locale/pt-BR'); // 🇧🇷 Brazil
const localeRU = require('@oxog/kairos/plugins/locale/ru-RU'); // 🇷🇺 Russia
const localeCN = require('@oxog/kairos/plugins/locale/zh-CN'); // 🇨🇳 China
const localeJP = require('@oxog/kairos/plugins/locale/ja-JP'); // 🇯🇵 Japan
const localeTR = require('@oxog/kairos/plugins/locale/tr-TR'); // 🇹🇷 Turkey

// Load and use locales
kairos.use([localeFR, localeES, localeIT]);

// Switch between locales dynamically
kairos.setLocale('fr-FR');
const date = kairos('2024-07-14');
date.format('LLLL'); // "dimanche 14 juillet 2024 00:00"
date.isHoliday(); // true (Fête Nationale)

// Each locale includes:
// ✓ Translated month/weekday names
// ✓ Date/time formatting patterns
// ✓ National holidays with local names
// ✓ Regional/state holidays
// ✓ Religious and cultural observances

Format Tokens

| Token | Output | Description | | ------ | ------- | -------------------- | | YYYY | 2024 | 4-digit year | | YY | 24 | 2-digit year | | MM | 01-12 | Month (padded) | | M | 1-12 | Month | | MMMM | January | Month name | | MMM | Jan | Month short | | DD | 01-31 | Day (padded) | | D | 1-31 | Day | | dddd | Monday | Weekday name | | ddd | Mon | Weekday short | | HH | 00-23 | Hour (24h, padded) | | H | 0-23 | Hour (24h) | | hh | 01-12 | Hour (12h, padded) | | h | 1-12 | Hour (12h) | | mm | 00-59 | Minutes (padded) | | m | 0-59 | Minutes | | ss | 00-59 | Seconds (padded) | | s | 0-59 | Seconds | | SSS | 000-999 | Milliseconds | | A | AM/PM | Meridiem | | a | am/pm | Meridiem (lowercase) | | Z | +00:00 | Timezone offset |

TypeScript

Kairos includes full TypeScript definitions with complete holiday support:

import kairos, { Kairos, HolidayRule, HolidayInfo } from '@oxog/kairos';
import holidayEngine from '@oxog/kairos/plugins/holiday/engine';
import localeUS from '@oxog/kairos/plugins/locale/en-US';

kairos.use([holidayEngine, localeUS]);

const date: Kairos = kairos('2024-12-25');
const isHoliday: boolean = date.isHoliday();
const holidayName: string | null = date.getHolidayName();
const holidays: HolidayInfo[] = kairos.getHolidays(2024);

Browser Usage

<script src="https://unpkg.com/@oxog/kairos/dist/kairos.min.js"></script>
<script>
  const date = kairos('2024-06-15');
  console.log(date.format('MMMM D, YYYY'));
</script>

Examples

See the examples/ directory for detailed usage examples:

• 01-fundamentals.js - Core concepts and basic operations
• 02-comparison-queries.js - Date comparisons and queries
• 03-formatting-display.js - Formatting options
• 04-business-calendar.js - Business day calculations with holiday awareness
• 05-durations-ranges.js - Duration and range operations
• 06-localization.js - Multi-locale support with 10+ languages
• 07-timezone-utc.js - Timezone handling
• 08-parsing-validation.js - Parsing strategies
• 09-relative-time.js - Human-readable time
• 10-advanced-plugins.js - Complex scenarios
• test-new-locales.js - Testing all available locales

🎯 Performance & Quality

Kairos is optimized for performance and reliability:

• Intelligent caching for repeated operations (LRU cache for holidays)
• Minimal object creation to reduce memory pressure
• Efficient algorithms for date calculations
• Tree-shaking support for smaller bundles
• 95%+ code coverage with comprehensive test suite
• Cross-platform testing on Windows, macOS, and Linux
• Performance benchmarks to prevent regressions

Testing

npm test           # Run all tests
npm run test:unit  # Unit tests only
npm run test:perf  # Performance tests
npm run coverage   # Coverage report

License

MIT

Contributing

See CONTRIBUTING.md for guidelines.

Support

• Issues: GitHub Issues
• Documentation: GitHub Wiki