Daily Drops of Dev Goodness
December is here, and with it comes the annual tradition of advent calendars tailored for the tech community. This year’s lineup is packed with daily challenges, insightful articles, and festive puzzles that cater to a wide range of interests, from front-end development to cybersecurity and beyond. Whether you’re looking to sharpen your skills or just explore something new each morning, there’s a calendar ready to fill your inbox or feed.
Hands-On Coding Challenges
For those who prefer writing code over reading about it, several calendars are structured as daily challenges.
- Advent of JavaScript: Sign up to receive a daily JavaScript challenge via email. Each task comes with all necessary HTML and CSS, letting you focus purely on the JavaScript. Briefs include getting-started steps and ways to push yourself further. Challenges are free, with paid solutions available.
- Advent of CSS: A companion calendar focused on CSS. Each daily email includes assets and a Figma design file to work from. A basic understanding of HTML and CSS is recommended before starting.
- Advent of Code: Created by Eric Wastl, this calendar offers a collection of small programming puzzles designed for various skill levels. Puzzles can be solved in any language. The only prerequisites are a little programming knowledge and problem-solving skills.
- 24 Pull Requests: A yearly initiative encouraging contributions to open-source projects from December 1st to 24th. The site now includes a form to record non-pull-request contributions, broadening the scope of what counts as a contribution.
- Code Security Advent Calendar: From SonarSource, this calendar serves up one code security puzzle or riddle per day. Participants are encouraged to discuss solutions with their networks via Twitter, with the most active players potentially receiving swag.
- Advent of Cyber: A beginner-friendly security calendar from TryHackMe. Each challenge grants you a raffle ticket, increasing your chances of winning a prize draw at the end of the month.
Curated Reading and Listening
Prefer articles and talks to puzzles? Several calendars collect and publish high-quality content throughout the month.
- JVM Programming Advent Calendar: Java Advent returns with a new article on a JVM-related topic every day. This project began in 2012 to provide technical content for JVM enthusiasts during the holiday period, making it a well-established resource.
- Perl 6/Raku Advent Calendar: Now in its 13th year, this calendar features articles on metaprogramming, applications, modules, programming techniques, container work, and migrations from Perl. The 2021 edition marks the sixth year since the project is known as Raku.
- HTMHell Advent Calendar: This calendar focuses on HTML, offering a daily mix of articles, talks, or tools. Alongside critiques of bad practices, Manuel shares good practices and useful tips.
- PerfPlanet Calendar: A performance-focused calendar running since 2009, offering content on all things speed and web performance. Contributions are currently being accepted.
- C# Advent Calendar: The fifth annual calendar features two pieces of C# content daily, including blog posts, videos, and podcasts. Contributions are open, with a standby list for authors.
- Lean UXMas: Publishing every advent since 2014, this calendar curates popular articles from the past year on Agile and Lean UX topics. Previous years' calendars are available for review.
- 24 Days in December: This calendar highlights the human side of PHP, featuring personal journeys and stories from within the "PHPamily." Now in its sixth edition, it is welcoming contributors to share their experiences.
Community and CMS Exclusives
Some calendars focus on specific platforms or community connections, offering unique content for niche audiences.
- Festive Tech Calendar 2021: With a growing YouTube subscription base, this calendar shares videos from diverse communities globally. It also houses a collection of content from past editions, showcasing a wide range of topics and speakers.
- Umbraco Christmas Calendar: Marking its 10th year, this calendar focuses on the "Friendly CMS." It offers a deep dive into Umbraco for those interested, with articles from previous years tagged by topic for easy navigation.
- Designcember: A celebration of UI development from web.dev. This calendar is crafted with CSS container queries and the new CQ Polyfill, and encourages interaction — from exploring window details to toggling dark mode or building your own demos.
- Inclusive Design 24: In the run-up to the New Year, this account is sharing favorite talks from previous #id24 online conferences. All videos have been manually re-captioned to ensure top quality.
Advent Calendars For Web Designers And Developers (December 2021 Edition)
Systems And Security
SysAdvent returns with its usual focus on sharing, openness, and mentoring. Each day brings a new article on systems administration, written by fellow sysadmins and covering the broad range of topics in the field.
The IT Security Advent Calendar kicks off with the credo "Don't store sensitive data in the cloud; keep it entirely disconnected from the web." 
Throughout December, it delivers a fresh tip each day for protecting devices, networks, and data.
Broader Tech And JavaScript
Bekk Christmas presents a mix of opinion pieces, tutorials, podcasts, and deep dives — 
the archives are worth exploring, with gems hidden in past editions such as 2020.
Calendars In Other Languages
Several calendars cover the web in languages beyond English:
24 Jours De Web (French)
24 Jours De Web first appeared in 2012 and has continued its tradition since. 
Twenty-four authors each publish an article on topics like UX, accessibility, and privacy.
SELFHTML Adventskalender (German)
This year's SELFHTML Adventskalender is dedicated to accessibility, a topic that concerns everyone — accessible websites are simply better websites. 
German-speaking developers can also bookmark the SELFHTML wiki for up-to-date documentation and tutorials.
adventJS (Spanish)
adventJS by Miguel Ángel Durán offers daily JavaScript programming challenges, all presented in Spanish. 
Started in 2015, participants are encouraged to share their solutions on Twitter.
Kodekalender (Norwegian)
Knowit has again brought its Norwegian calendar to life. 
Each hatch hides a task to answer as a text string or number, best solved with code. Difficulty varies, and solving enough doors boosts your chances of winning.
WEBアクセシビリティ Advent Calendar (Japanese)
Moderated by @hokaccha, this Japanese calendar has run since 2013. 
It focuses on web accessibility, with authors covering a range of topics each day. Once logged in, you can claim a day and publish your own article. If you know of other non-English calendars, feel free to reach out on Twitter.
Closed Calendars Worth Revisiting
Christmas Experiments (2018)
Christmas Experiments began in 2012, delivering daily WebGL experiments crafted by digital artists. Despite its success, the project ended after the 2018 edition.
24 Accessibility (2019)
24 Accessibility hasn't published since 2019, but remains a solid resource. 
Articles cover digital accessibility from an angle relevant to designers, developers, UX professionals, QA analysts, and project managers alike.
It's A Shape Christmas (2019)
It's A Shape Christmas, started in 2011 by UK design agency Made by Shape, reveals a bespoke illustration daily themed around four shapes — Square, Triangle, Circle, and Hexagon. 
The site still shows highlights from past seasons.
24 Ways (2019)
Initiated by Drew McLellan, 24 ways published a daily tip or trick each December since 2005. Its last edition ran in 2019, but all past calendars remain online. 
Perl Advent (2020)
Perhaps the longest-running web advent calendar, the Perl Advent started in 2000. 
It features a different Perl module daily, with an extra module on Christmas day. The full archives are available.
PWAdvent (2020)
PWAdvent introduced a new progressive browser feature each day last year, curated by Nico Martin and others, aimed at fans of the web platform and Progressive Web Apps.
A11y Advent Calendar (2020)
Kitty Giraudel's #A11yAdvent offered an accessibility tip each day last year. 
Some tips may be common knowledge to many, but they cover important aspects of accessibility that remain relevant.
A Final Word
Finally, the Smashing team has joined in with #SmashingAdvent to spotlight favorite talks and interviews from its conference history. 
Follow @SmashingConf to catch those. Thanks to everyone involved in these projects — your time and dedication sustain the web community. If there's a calendar missing here, please share it in the comments.
