As the saying goes: a picture often tells more than a thousand words. This is certainly true for graphical timelines. A detailed listing of events and dates in tabular form may offer the reader a lot of specifics, but may fail to provide an overview, a grand perspective.
I have devised a simple yet flexible script syntax for defining time chart input.
A user writes an input script, runs EasyTimeline (invokes other free sw) to generate the chart and uploads chart and script to Wikipedia. Someone else can download and modify the script, generate a new or translated version of the chart, and upload chart and script back to Wikipedia.
Examples and details at http://members.chello.nl/epzachte/Wikipedia/EasyTimeline/Introduction.htm
Please comment at http://meta.wikipedia.org/wiki/Wikipedia_Project_Time_Charts
Erik Zachte