Answer: May 16
Notes: The International Day of Light 2025 is observed globally on May 16 with the theme “Light, Innovation, Society.” Events were held at the United Nations Educational, Scientific and Cultural Organization (UNESCO) Headquarters and worldwide to highlight light’s role in science and sustainability. The day was first celebrated in 2018 after being proposed by Ghana, Mexico, New Zealand, and Russia, and approved by UNESCO in 2017. It aims to raise awareness about light-based technologies and promote science, innovation, and the United Nations Sustainable Development Goals (SDGs).
