I've just added code to show up to 7 days of track data on the map when looking at a single tracking target. Thanks to Steve, K9DCI on the APRSSIG for reminding me about this. :) This only works for single target views, since longer time range searches for global data would place a heavy load on both the database, as well as the web browser.
Showing the track wasn't hard. As usual, getting the user interface to work on MSIE was. Found out the hard way that the disabled attribute isn't working on the select list used for time range selection, so I had to resort to completely removing entries which are not usable.
Update on Friday, 8th of August: I just realized it doesn't work with the date selection menu - I will fix that one later.