The point of it
The idea is to study how different key words in a database rise and fall in prominence through time as the words in a concordance timeline do. The procedure requires your texts to differ in date.
How to do it
With a keyword database loaded you can simply choose Compute | Timeline, specify the periods of time and press OK. If you need to change the dates of the text files, see setting text dates.
This is a timeline showing data from the novel Bleak House. At the top we have overall data showing the amount of text and number of key words in all the 16 months between May 1852 when Dickens started writing it, to August 1853 when he finished.
Timelines for the individual key words in the database vary. The character GEORGE appears as a key character from Sept 1852 to the end of that year, and again in the following Spring.
For further explanation of the lines and colours see the section on concordance timelines.