Explanation

• The Gregorian calendar is the most widely used civil calendar worldwide today.
• It was introduced by Pope Gregory XIII in 1582.

Additional information:

• Julian Calendar: Introduced by Julius Caesar in 45 BC.

Last verified on 14-10-2026

Explanation

• Date: April 22
• First Held: April 22, 1970
• Purpose: Raise awareness for environmental protection and conservation
• Theme 2026: Our Power, Our Planet 

Explanation

• World Health Day is observed on 7th April every year.
• Theme 2025: Healthier beginnings, hopeful futures
• Theme 2026: Together for health. Stand with science

Additional information: 

• World Health Organization (WHO) was founded on 7 April 1948.
• WHO has its headquarters in Geneva, Switzerland.

Last verified on 12-10-2026

Explanation

• World Braille Day is observed on 4 January every year.
• The first World Braille Day was celebrated on 4 January 2019.
• The day recognizes the contribution of Louis Braille in helping blind and visually impaired people read and write.

Last verified on 08-10-2026

Explanation

• International Day of Older Persons is observed on 1 October.
• This day was proclaimed by UNGA in 1990.
• Theme 2025: Older Persons Driving Local and Global Action: Our Aspirations, Our Well-Being and Our Rights
• Theme 2026: The Age of Longevity: Rethinking Systems for Longer Lives
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