Node.js

Installation

npm install date-wiz

Works with both require() (CommonJS) and import (ESM).

---

ESM (recommended)

// script.mjs  — or any .js file with "type": "module" in package.json
import { format, addBusinessDays, getRelativeTime } from 'date-wiz';

console.log(format(new Date(), 'DD MMM YYYY'));
// → "15 Mar 2026"

CommonJS

script.js

const { format, addBusinessDays, getRelativeTime } = require('date-wiz');

console.log(format(new Date(), 'DD MMM YYYY'));
// → "15 Mar 2026"

---

Express API — formatted timestamps

import express from 'express';
import { smartFormat, getRelativeTime } from 'date-wiz';

const app = express();

app.get('/posts', async (req, res) => {
  const locale = req.headers['accept-language']?.split(',')[0] ?? 'en';

  const posts = await db.getPosts();

  res.json(posts.map(post => ({
    ...post,
    displayDate: smartFormat(post.createdAt, { locale }),
    relativeDate: getRelativeTime(post.createdAt, { locale }),
  })));
});

---

SLA report script

import { addBusinessDays, countBusinessDays, format, checkIsBusinessDay } from 'date-wiz';

const PUBLIC_HOLIDAYS = [
  '2026-01-01', // New Year
  '2026-03-26', // Independence Day (Bangladesh)
  '2026-12-25', // Christmas
];

function generateSLAReport(tickets: Array<{ id: string; opened: Date }>) {
  return tickets.map(ticket => {
    const deadline = addBusinessDays(ticket.opened, 5, {
      holidays: PUBLIC_HOLIDAYS,
    });
    const businessDaysLeft = countBusinessDays(new Date(), deadline, {
      holidays: PUBLIC_HOLIDAYS,
    });

    return {
      id: ticket.id,
      opened: format(ticket.opened, 'YYYY-MM-DD'),
      deadline: format(deadline, 'YYYY-MM-DD'),
      businessDaysLeft,
      isBreached: businessDaysLeft < 0,
    };
  });
}

---

Cron job — only run on business days

import cron from 'node-cron';
import { checkIsBusinessDay, isWithinWorkingHours } from 'date-wiz';

// Run every 30 minutes, but only process during business hours
cron.schedule('*/30 * * * *', () => {
  const now = new Date();

  if (!checkIsBusinessDay(now)) {
    console.log('Weekend — skipping');
    return;
  }

  if (!isWithinWorkingHours(now, { start: '09:00', end: '18:00' })) {
    console.log('Outside working hours — skipping');
    return;
  }

  processQueue();
});