Holiday Optimizer

A plan in Holiday Optimizer: each card is one break, built from leave days, public holidays and weekends.

Holiday Optimizer is a free, privacy-first web app that turns your annual leave into the longest possible stretches off. It analyzes public holidays and weekends and tells you exactly which days to book to maximize consecutive days away from work. It’s a live product at holiday-optimizer.com, and the original open-source version has more than 500 stars on GitHub.

What it does

You enter how many leave days you have and pick your region; the optimizer finds the leave dates that chain together with public holidays and weekends — the “bridge days” — to produce the most total time off per day spent. Everything runs locally in your browser: no account needed, and no leave data ever leaves your device.

• Leave optimization — suggests the dates that maximize consecutive days off for the leave you have
• Multi-region public holidays — accurate holiday data for many countries and regions
• Visual calendar — see the resulting breaks at a glance, with an efficiency metric (days off gained per leave day used)
• Privacy-first — all calculations happen in-browser; preferences are stored in local storage

Press

• Travel + Leisure — “Maximize Your PTO in 2026 With This Travel Hack”, Dec 2025. Cites Holiday Optimizer’s finding that an employee with 11 vacation days could unlock 41 days off in 2026.
• The Washington Post — “How to get the most days off with your vacation time in 2026”, Jan 2026.
• Real Simple — “Smart Ways to Maximize Your PTO, According to Science”, Mar 2026.

How it’s built

A static site with all the work done in the browser:

• Frontend — Next.js, React, TypeScript, and Tailwind CSS, exported as a static site
• Optimization — runs entirely client-side using the bundled date-holidays library, so the holiday math never hits a server
• Hosting — static files on AWS S3 behind CloudFront, deployed from GitHub Actions
• Analytics — PostHog, consent-based, sent through a same-origin relay

FAQ

How does it decide when I should take leave? It scans the year’s public holidays and weekends for your region and finds the leave dates that link them into the longest unbroken stretches off, then ranks the suggestions by efficiency — total days off per leave day spent.

Is my data private? Yes. All optimization runs locally in your browser; your leave days and preferences are never sent to a server.

What does it cost? The planner is free to use.

Which regions are supported? Public-holiday data is bundled for many countries and regions, selectable when you plan.

Why I built it

Most people leave consecutive days off on the table because lining leave up with public holidays by hand is tedious. I wanted to solve that real, recurring problem — and ship a complete product end to end: a client-side optimization algorithm, a paid calendar export running on AWS Lambda (since retired), and privacy-first analytics.