Units of time are used to measure the passing of time and can range from very small increments such as ticks to much larger ones such as EONS. Ticks, which have five letters, are the smallest unit of time and measure a very short period of time, usually one thousandth of a second. Issues, with six letters, is a term used to describe a period of twelve years. EONS, with four letters, is an incredibly long period of time, usually millions or billions of years. HOURS, with five letters, is a unit of time that is commonly used to measure the passing of a day and is equal to sixty minutes. Weeks, with five letters, is a unit of time that is equal to seven days.