Q. Which month is 29 days

February is the only month that has 29 days, but only during leap years, which occur every four years (with rare exceptions). In regular years, February contains just 28 days, making it the shortest month of the calendar. The leap year system adds an extra day—February 29th—to keep the calendar synchronized with Earth's 365.25-day orbit around the sun, preventing seasonal drift over time.

Leap years follow a specific rule: a year is a leap year if it's divisible by four, except for century years, which must be divisible by 400. This means 2000 and 2024 were leap years, while 1900 and 2100 are not. The 29-day February affects everything from birthday celebrations for those born on the 29th to payroll calculations and contract durations, making it a unique quirk of our timekeeping system that serves an essential astronomical purpose.