localized-greeting

Time-of-day greetings ("Good morning", "Guten Tag", "Bonsoir") in the user's locale. Zero runtime dependencies. Works in Node 18+ and modern browsers.

Install

npm install localized-greeting

Basic usage

import { getGreeting, getTimeOfDay } from 'localized-greeting';

// Uses the runtime locale and current time automatically
console.log(getGreeting());                          // e.g. "Good morning"

// Explicit locale
console.log(getGreeting({ locale: 'de' }));          // "Guten Morgen"
console.log(getGreeting({ locale: 'fr' }));          // "Bonjour"

// Explicit date
const d = new Date('2024-01-01T20:00:00');
console.log(getGreeting({ locale: 'es', date: d })); // "Buenas noches"

// Just the time bucket
console.log(getTimeOfDay());                         // "morning" | "afternoon" | "evening"

Custom locale registration

import { registerLocale, getGreeting, getSupportedLocales } from 'localized-greeting';

registerLocale('ja', {
  morning: 'おはようございます',
  afternoon: 'こんにちは',
  evening: 'こんばんは',
});

console.log(getGreeting({ locale: 'ja' })); // "おはようございます" (in the morning)
console.log(getSupportedLocales());          // [..., 'ja']

registerLocale can also override a built-in locale at runtime.

Locale resolution

1. Try the full BCP 47 tag (e.g. de-AT).
2. Try the base language (de).
3. Fall back to en.

Underscores are normalised to hyphens (de_AT → de-AT) and matching is case-insensitive.

When no locale option is passed, the library reads Intl.DateTimeFormat().resolvedOptions().locale (the system/browser locale) and falls back to "en" if unavailable.

Note: Time-of-day detection uses the local system clock of the environment running the code (Node.js process or browser tab). The date option lets you override this with any Date object.

Time buckets

| Hour range | Bucket | | ---------- | ----------- | | 05 – 11 | morning | | 12 – 17 | afternoon | | 18 – 04 | evening |

Built-in locales

en, de, es, fr, it, pt, nl, sv, da, pl

API

type TimeOfDay = 'morning' | 'afternoon' | 'evening';
type GreetingTranslations = Record<TimeOfDay, string>;

interface GreetingOptions {
  locale?: string; // BCP 47, defaults to runtime locale then "en"
  date?: Date;     // defaults to new Date()
}

function getGreeting(options?: GreetingOptions): string;
function getTimeOfDay(date?: Date): TimeOfDay;
function registerLocale(locale: string, translations: GreetingTranslations): void;
function getSupportedLocales(): string[];

Development

npm install
npm run build      # tsup → dist/
npm test           # vitest
npm run typecheck  # tsc --noEmit
npm run lint       # eslint
npm run format     # prettier

License

MIT