Dear Steve, 

I came across a free program that calculates midpoints. If anybody is 
interested in getting it, they can email me for details. Regards, Ron 

Ronald Bromley ron@panther.netmania.co.uk 

[ Note from Steve:  Thanks Ron.  I also have used a free service, 
based in The Netherlands I believe, and I think that the link is on my 
web site (see "Links").  It would calculate transits to a natal chart 
for any past time older than a week, i.e., not a prediction.  Perhaps 
it is the same site that you know of...  ] 
 
Be sure to see Ron's web site, under "Links" 
        - there are several free midpoint programs for you to download.