The short answer is - you don't. The internal clock in Project begins at
zero on Jan 01 1984 and runs to 31 Dec 2049 and that defines the date range
possible in Project. Perhaps start your plan file in '84 with the notation
"Before this time there was naught but chaos, and darkness was upon the
land." To be honest, I can't imagine the practical need to produce detailed
task lists of events that far back in history - IMO, project scheduling is
focussed on the future and detailing historical events in the plan back that
far has little practical purpose in planning today for the future work in
the project.
If you're simply trying to create a Gantt chart type of representation of
historical events and can forgo Project's detailed planning and management
abilities you could build it in a graphics tool like Visio which does allow
for earlier date ranges. In Visio 2003's Gantt chart wizard you can start
as early as 1900. The date range is divided into major and minor units,
months and days or years and weeks for example, and the length of the scale
is limited by whatever date range that results in there being 999 or less
minor unit divisions. That means if you can live with a timescale graduated
in years and months you can begin 01 Jan 62 and go out as far as Jan 2045,
going with a minor division of weeks will max out the scale in '84 while a
minor unit of days will max out in late '64.
Must be a bodacious project to have begun 45 years ago and still be going on
today.
HTH
