International Day of Light
Light science and technology illuminating our future.
About
The International Day of Light is celebrated on May 16 — the anniversary of the first successful operation of the laser in 1960 by physicist Theodore Maiman. The day recognises the role light plays in science, culture, art, education, and sustainable development — from fibre optic communications and solar energy to medical imaging and astronomical observation.
History
UNESCO proclaimed May 16 as the International Day of Light in 2017, building on the success of the International Year of Light in 2015. The laser anniversary was chosen to reflect both the scientific history of light and its transformative applications. Events worldwide include light art installations, open days at photonics labs, and science outreach in schools.
Where It's Observed
How to Participate
- 01Learn how lasers work and how they are used in everyday life
- 02Explore how light-based technologies power the internet and medicine
- 03Experiment with prisms, rainbows, or simple diffraction gratings at home
- 04Visit a science museum with optics or photonics exhibits
Frequently asked questions
When is International Day of Light?+
International Day of Light is observed annually on May 16. The date is fixed each year — May 16 — and does not shift based on the lunar calendar or weekday.
What is International Day of Light?+
The International Day of Light is celebrated on May 16 — the anniversary of the first successful operation of the laser in 1960 by physicist Theodore Maiman. The day recognises the role light plays in science, culture, art, education, and sustainable development — from fibre optic communications and…
Is International Day of Light a public holiday?+
International Day of Light is an international observance or awareness day, not a public holiday in most countries. It does not typically result in days off work or school closures, though some countries and organisations hold official events.
How can I participate in International Day of Light?+
Learn how lasers work and how they are used in everyday life Explore how light-based technologies power the internet and medicine Experiment with prisms, rainbows, or simple diffraction gratings at home These are some of the most accessible ways to engage with the day's purpose.
Which countries observe International Day of Light?+
Global — UNESCO initiative.
Mark the date
Download a free printable calendar for 2026 and never miss International Day of Light.