sl-date-utils-v1 🇱🇰

Utility functions for handling Sri Lankan holidays, working days, Sinhala calendar months, and Poya day calculations.

✨ Features

• 🇱🇰 Sri Lanka public holidays (with dynamic multi-year support)
• 🏖️ Filter holidays by category (Public, Bank, Mercantile)
• 📅 Check if a date is a holiday
• 🧮 Calculate working days between two dates (excluding weekends & specific holiday categories)
• 🗓️ Get the Sinhala month for any date
• 🌕 Get the Poya day for a given month
• 🔍 Find all holidays in a given year or month
• ⏩ Get the next upcoming holiday
• 💡 Simple & lightweight
• ✅ Full TypeScript support

📦 Installation

npm install sl-date-utils-v1

🚀 Usage

1. Checking Holidays

Check if a specific date is a holiday. Optionally, filter by category:

import { isHoliday } from 'sl-date-utils-v1';

isHoliday("2026-05-01"); // true (May Day)

// Check if it's specifically a mercantile holiday
isHoliday("2026-04-03", ["mercantile"]); // false (Good Friday is Public/Bank only)

2. Calculating Working Days

Get the number of working days between two dates. Weekends and holidays are excluded.

import { getWorkingDays } from 'sl-date-utils-v1';

// Get working days (excludes ALL holidays by default)
getWorkingDays("2026-04-01", "2026-04-30");

// Get working days (excludes only Mercantile holidays)
getWorkingDays("2026-04-01", "2026-04-30", ["mercantile"]);

3. Extended Holiday Utilities

import { getHolidaysForYear, getHolidaysForMonth, getNextHoliday } from 'sl-date-utils-v1';

// Get all holidays in 2026
const holidays2026 = getHolidaysForYear(2026);

// Get all Bank holidays in April 2026
const aprilBankHolidays = getHolidaysForMonth(2026, 4, ["bank"]);

// Get the next upcoming holiday from a specific date
const next = getNextHoliday("2026-02-10");
console.log(next?.name); // e.g., "Maha Sivarathri Day"

4. Sinhala Months & Poya Days

import { getSinhalaMonth, getPoyaDay } from 'sl-date-utils-v1';

getSinhalaMonth("2026-04-14"); // "Bak"
getPoyaDay("2026-05"); // "2026-05-01" (Vesak Poya)