A timeline is another way of looking at time.
Timelines are timetables or chronologies of key events in a period of history.
Timelines can also be used to plan future events - for example timelines for a project could document when various parts of a project should be started or completed. Below is a simple time denoting when the thirteen colonies were admitted as states. The data is arranged in chronological order - that is from the first or earliest date to the last or latest date, which is typical for timelines. Timelines can be arranged vertically or up and down as this one or horizontally. The range of dates can be narrow as this one which spans under twenty years or can be over millions of years as with geological timelines of prehistoric times.