¿Por qué hay años bisiestos?

The video explains the concept of a leap year, established by Pope Gregory XIII, due to the Earth's orbit taking slightly more than 365 days. It discusses the need for leap years to keep the calendar aligned with astronomical positions, detailing the rules and exceptions for leap years, such as years divisible by 100 not being leap years unless divisible by 400. The video concludes with a call to subscribe and follow on social media.

Who established the leap year and when?

What would happen if we did not have leap years?