VS Code
CodePen
GitHub
Node.js
RegExr
JSFiddle
CodeSandbox
Free ebook for the JS Beginners

Date Calculator Pro
28 Days from Today
CountBusinessDays
clocks.life
Working Days Calc
Biz Day Calc
WeekIsIt
The current day number, week number, and today's date. What day of the year it is and remaining days in the year. Date calculator, Calendar & Time formats.

Which is more popular?
Based on our record, Eloquent JavaScript seems to be more popular. It has been mentioned 218 times since March 2021.
Website, pricing, platforms and company facts side by side.
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EJS
Eloquent JavaScript
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| Website | eloquentjavascript.net | day-number.com |
| Pricing | ||
| Company | — | 2025 |
| Listed in |
In their own words, as submitted to SaaSHub.

No description of Eloquent JavaScript yet.
Check the current day number, week number, and today's date. Learn which day/week of the year it is and how many days/weeks remain in the year. Date calculator. Auto-detects time zone/country, updates in real-time per ISO standards, suiting developers, students, businesses (payroll), and...
What each product offers, as listed by its team.

Possible disadvantages
An editorial look at what each product does well and who it suits.

Overall verdict
Why this product is good
Recommended for
Overall verdict
Why this product is good
Recommended for
Walkthroughs and reviews on video.
Eloquent JavaScript A Modern Introduction to Programming 3rd Edition by Marijn Haverbeke review
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How often each product is chosen within a category, 0–100% relative to the other.

As answered by people managing Eloquent JavaScript and Day-Number.
Day-Number's answer:
Day-Number automatically detects your timezone and location, then displays ISO 8601-compliant day numbers, week numbers, and country-specific holidays - all in one place. Unlike basic calendar tools, we combine real-time timezone intelligence with international holiday support and powerful date calculators in a clean, modern interface.
Day-Number's answer:
We automatically detect your location and adjust everything for you - perfect for travelers and remote workers. We provide accurate ISO week numbers (which many tools get wrong), support multiple date format standards, show upcoming holidays for your country, and include powerful date calculators. Everything is free, privacy-focused, and works beautifully across all devices.
Day-Number's answer:
Remote workers and digital nomads managing multiple timezones, developers and project managers who work with ISO date standards, international teams coordinating across different countries, and anyone who needs quick access to standardized date information without complex calendar apps.
Day-Number's answer:
As developers working with international teams, we constantly needed to answer "What's today's ISO week number?" or "How many days until the deadline?" Existing tools either lacked timezone intelligence or showed incorrect ISO calculations. We built Day-Number as the tool we wished existed - one that instantly shows where you are in time, no matter where you are in the world.
Day-Number's answer:
Next.js 15 with React 19 and TypeScript for performance and maintainability, Tailwind CSS for responsive design, date-fns-tz for precise timezone calculations, and next-intl for internationalization. We use ipapi.co for geolocation and Nager.Date for holiday data, deployed on Vercel's edge network for global availability.
Day-Number's answer:
As a free public tool, we serve thousands of individual users rather than traditional customers - including developers relying on accurate ISO standards, international businesses managing multi-timezone operations, and remote-first companies. We're adopted particularly in tech hubs across North America, Europe, and Asia, especially among digital nomad communities.
Share your experience with using Eloquent JavaScript and Day-Number. For example, how are they different and which one is better?
Recommendations tracked on public social media and blogs since March 2021.

If you haven’t read Eloquent JavaScript , go check it out. It’s one of my all-time favourite programming books — hands down. - Source: dev.to / about 1 year ago
Videos, blogs, text-based teachings, YouTube project-based learning, books, and the like are all examples of various methods and mediums of acquiring skills, especially in the software engineering industry. As I continue to navigate... - Source: dev.to / almost 2 years ago
Seconded. I won't recommend it and no one I know has recommended it for a decade. It's hard for someone who doesn't know JS to know which parts has changed and is no longer the way to do things. https://github.com/getify/You-Dont-Know-JS... - Source: Hacker News / about 2 years ago
Tracking Day-Number since Nov 2025.
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