Shop our 2024 calendars. Now available for purchase!
Image for International Day of Light

International Day of Light

Also known as

  • IDL



Founded by


  • Awareness & Advocacy

  • Science & Technology



The International Day of Light is "a global initiative that provides an annual focal point for the continued appreciation of light and the role it plays in science, culture and art, education, and sustainable development, and in fields as diverse as medicine, communications, and energy." Disparate sectors of society worldwide participate in activities that demonstrate how technology, science, art, and culture can achieve UNESCO's goals of education, equality, and peace. The event is administered by a steering committee of UNESCO's International Basic Science Programme (IBSP) which includes many international partners.

According to the International Day of Light's website, the day's goals are to:

  • Improve the public understanding of how light and light-based technologies touch the daily lives of everybody, and are central to the future development of the global society.
  • Build worldwide educational capacity through activities targeted on science for young people, addressing issues of gender balance, and focusing especially on developing countries and emerging economies.
  • Highlight and explain the intimate link between light and art and culture, enhancing the role of optical technology in preserving cultural heritage.
  • Enhance international cooperation by acting as a central information resource for activities coordinated by learned societies, NGOs, government agencies, educational establishments, industry, and other partners.
  • Emphasize the importance of basic research in the fundamental science of light, the need for investment in light-based technology to develop new applications, and the global necessity to promote careers in science and engineering in these fields.
  • Promote the importance of lighting technology and the need for access to light and energy infrastructure in sustainable development, and for improving quality of life in the developing world.
  • Raise awareness that technologies and design can play an important role in the achievement of greater energy efficiency, in particular by limiting energy waste, and in the reduction of light pollution, which is key to the preservation of dark skies.

The International Day of Light is held on May 16 because it was on that date in 1960 that a laser was first operated successfully, by Theodore Maiman, a physicist and engineer. The laser is relevant because it is an example of a scientific discovery related to light that has benefited society in many ways. But the International Day of Light is not just about science—it is about anywhere light can be found, such as in art culture, entertainment, and education.

In 2015, the International Year of Light and Light-based Technologies 2015 (IYL 2015) was observed. Organized by UNESCO, this UN observance raised awareness about the achievements of light science and its applications. Over 13,000 activities were held in 147 countries. Following its success, moves were made to create an International Day of Light. On September 19, 2016, a resolution supporting the day was adopted by the UNESCO Executive Board at the UNESCO headquarters in Paris. The resolution was endorsed by the UNESCO General Conference at its 39th session, on November 7, 2017. The International Day of Light was first observed in 2018. Over 600 events were held in 87 countries, and a main event was held at the UNESCO headquarters.

How to Observe International Day of Light

A few ways to get involved with the International Day of Light include:

Exclusive Content

Enjoying Checkiday? It takes a lot of support from fans like you to run a free website. For exclusive content and other perks, please consider supporting us on Patreon. Thank you!


This event does not currently have a sponsor. If you'd like to increase visibility for this event while gaining exposure for yourself or your brand, you can learn more here!

Something Wrong or Missing?

We would love to hear from you! Please contact us using this form.

Observation Notifications

Would you like to be notified before the next observation? Add this event directly to your calendar with this link. You may also sign up here to be told when other notifications are available!

Also on this date…