An annual calendar is a type of calendar that is used to track the days, months, and years of a given period. The term can be broken down into four parts: ALMANAC (7 letters), DAY (3 letters), MONTH (5 letters), and Year (4 letters). An ALMANAC is a book or table containing important information such as astronomical data, tide tables, and other statistical information. A DAY is a 24-hour period of time, usually measured from midnight to midnight. A MONTH is a unit of time, typically between 28 and 31 days in length. Finally, a year is a unit of time equal to 365 or 366 days. Together, these four components make up an annual calendar, which is used to keep track of the days, months, and years of a given period.