One of my favourite ways of representing time is using the bar as timeline and to specify an empty dot on it to make relevant a notorious moment.
Here a very easy example on how to get to represent the evolution of architechure and spaces along the 20th century. This example is also one of my favourite one in order to explain time on infographics. The repetition and insistence on a colour key is used in order to provide a clear and easy to follow language, so the information ca be quickly found.
Project published in 2008
David López Álvarez 