Research Gantt Chart. http://en.m.wikipedia.org/wiki/Gantt_chart
Search this forum and using your favorite search engine, the phrase: "FileMaker Gantt chart" (no quotes).
-- sent from my iPhone4 --
If you think of the chart as being 365 days and each item has a start that is x number of days since day zero on 1/1/yy and a duration of x number of days.
Those number of days are %ages of 365...