Maintaining Physically Identical Intervals Over Multiple Timelines

[Cartaphilus]

If I drag a timeline object onto my Visio page and configure it to display
the date range 1 June 2006 through 1 January 2007, Visio will display the
timeline with 6 equally spaced intervals. If I then reconfigure the timeline
to display 1 June 2006 through 1 June 2007, the default behavior is that the
length of the timeline overall remains the same and the length of each
interval is cut in half. Is there any way to make the default behavior
maintain the same physical length for each interval and expand the overall
length of the timeline instead?

Or perhaps there's a better way to accomplish what I'm trying to do. What I
want to do is put a major timeline of at least a couple of years across the
top of the page and then track an entire portfolio of projects against that
timeline. Each project would be an individual timeline below the major one,
and each would start and end at different times. And if 6 individual
projects in the portfolio are all running concurrently on several months, I
want all 6 to have their common monthly intervals line up on the same
vertical axes (June to June, July to July, etc.). This would require that
the physical spacing of one month interval lines on each timeline be
identical.

Any suggestions?

Thanks...