Very similar to How can I keep the original file [commit] timestamp on Subversion?, but I'm interested in preserving the timestamp on the commit side rather than propagating it on the checkout / update side.
Specifically, I'm checking some (very old) unversioned files into my shiny new SVN setup, so I'll have everything in one place, but I want their timestamps to reflect the actual modified times rather than the time I loaded them into the system (which will be virtually the same for all of them).
Are there any solutions for this? I've searched and searched the SVN documentation available online but haven't found anything that seems to do what I want.