This stands in contrast to Queen Elizabeth II, who famously continued riding horses well into her 90s, with reports of her still riding at age 96 just months before her passing.
Why the Parade Happens in June—Not November

Though King Charles was born on November 14, the annual Trooping the Colour is celebrated in June. This practice, established in the 18th century, separates the monarch’s actual birthday from their “official birthday”—largely for a practical reason: better weather.
British monarchs have long chosen to hold the parade in early summer to avoid the dreary, wet conditions common in autumn. Queen Elizabeth II also observed this tradition by celebrating her official birthday on the second Saturday of June.
Whether Prince William, who was actually born in June, will maintain the two-birthday tradition when he becomes king remains uncertain. Some royal watchers speculate he might modernize or even abandon the custom altogether.
What This Signals About the Modern Monarchy

The King’s decision to opt for comfort over custom may seem small, but it’s telling. It reflects the ongoing balancing act between royal tradition and personal well-being in a new era of the monarchy.
While Trooping the Colour remains one of the most visually grand events on the royal calendar, this year’s edition will carry a quiet shift in tone—reminding the public that even age-old traditions must sometimes evolve with the times.