One year is a unit of time that consists of 365 days, or 366 days in a leap year. It is commonly divided into 12 months, each varying in length from 28 to 31 days. The year is a fundamental measure used in calendars, such as the Gregorian calendar, which is widely used around the world. In many cultures, a year marks the completion of seasonal cycles, including spring, summer, autumn, and winter. It is also significant for various events, such as birthdays, anniversaries, and holidays like New Year's Day. Each year brings changes in weather, nature, and personal experiences.