Why do some months have 30 days and others 31?
Quick Answer: Months have 30 or 31 days because of how the Roman calendar was structured. Julius Caesar adjusted the calendar to align with the solar year, giving most months 31 days and some 30 to keep things balanced and consistent throughout the year.
The calendar we use today is based on the Julian calendar, created by Julius Caesar in 46 BC. Before that, the Roman calendar was a mess, with months varying widely in length. Caesar wanted a system that matched the Earth's orbit around the Sun, which takes about 365.25 days.
To fix this, he made most months either 30 or 31 days long, except February. This way, the total days in a year added up properly. The pattern stuck around and carried into the Gregorian calendar we use now, which is why some months have 30 days and others 31.