Bengaluru Zero Shadow Day 2025: Date, Time, and How to See; All You Need to Know

If you're in Bengaluru on 24th April, your shadow will vanish right in front of your eyes at 12:17 pm. No, we are not making this up. People in Bangalore are in for a rare celestial treat on Wednesday as the city will experience the fascinating Zero Shadow Day phenomenon. It is an event where vertical objects will cast no shadow at all, but only for a brief moment. The Indian Institute of Astrophysics (IIA) has confirmed that this will happen exactly at 12:17 PM, when the sun will be directly overhead.

What is Zero Shadow Day?

To put it simply, Zero Shadow Day occurs when the sun is positioned exactly at the top of the sky, at a 90-degree angle to the Earth's surface. This angle causes sunlight to fall straight down, meaning vertical objects like poles, sticks, or buildings don't cast any visible shadow beside them. Instead, the shadow falls directly beneath and becomes invisible to the human eye.

According to the Indian Institute of Astrophysics (IIA), Zero Shadow Day happens twice a year for all locations situated between the Tropic of Cancer and the Tropic of Capricorn.

Niruj Mohan Ramanujam, Head of IIA's Science Communication, Public Outreach, and Education (SCOPE) division, informed PTI that the zero shadow phenomenon in Bengaluru will be visible on April 24 at 12:17 PM, when the sun will be exactly overhead, eliminating shadows altogether.

Why Zero Shadow Day Happens in Bengaluru?

Bengaluru, like other cities such as Chennai and Mangaluru, lies south of the Tropic of Cancer, making it eligible for this fascinating celestial event. As the Earth revolves around the sun on a tilted axis, the sun's position in the sky changes slightly every day. It moves northward and southward between the Tropic of Cancer (23.5° N) and the Tropic of Capricorn (23.5° S). When the sun's position, or declination, perfectly matches the latitude of a city, the sunlight falls vertically, causing shadows to disappear. So, in Bengaluru, where the latitude is about 12.97°N, this perfect alignment happens twice a year-once when the sun moves north and again when it moves south. One of those days falls on April 24 in 2025.

How to Observe Zero Shadow Day in Bengaluru

You don't need a telescope or any fancy gear to witness Zero Shadow Day. Here's how you can easily observe it at home, school, or the office. Just find a vertical object like a bottle, pole, pencil, or stick and place it on a flat surface outdoors, and at exactly 12:17 PM, observe the shadow, which will shrink directly below the object and disappear for a few seconds.

Many schools and science organisations across Bengaluru and South India are expected to host awareness events and solar observations to help people witness and learn about this phenomenon.