Questions says it all. I've looked in site and app prefs, but can't find anything. Seems like a no brainer for such a nice FTP app, so I gotta think I'm just missing it.
I was looking for this same answer myself. I eventually found this in an FAQ list on the Panic site:
In my case, there were no server settings, just a "default" setting, but since I always wanted the modification dates preserved (in order to sync changes to web sites from different machines), that was fine for me.
Hope this helps.
Can you put the files into a tar, do the ftp transfer and then untar? This way the timestamps will be preserved.