Please try the 3.2.16-svn9210 build, available here: vassalengine.sourceforge.net/builds/
After you save a module, there will be some diagnostic information in the errorLog. Please send me that.
Sorry for the delay. I had some trouble reproducing first time I tried. I edited a fresh copy of CC:E v2.3 module from this site, and the zip file is partially reset to datetime 0 (not all the files this time).
[attachment=1]Screen Shot 2016-03-16 at 14.40.22.jpg[/attachment]
[attachment=0]errorLog.txt.zip[/attachment]
The times printed in the log are all ns since the epoch. The bad time I’m seeing in the log is 315529200000, which ‘date -d @’ tells me is Mon Dec 31 23:00:00 UTC 1979.
When I look at a fresh download of the same module, what I see is quite a few files with mtimes set to 00:00 1 January 1980 already. From what I can see in the log, those mtimes are being passed through correctly into the module you’ve saved.
So, I believe the problem is fixed as of svn9210. I’ll see about releasing 3.2.16 containing this fix sometime in the next few days.
Outstanding!
Fascinating. I remember exactly where I was, that New Years Eve. Sitting at the kitchen table in my apartment in Queens, New York City, playing The Russian Campaign - solo. A good time was had by all. 
I’m getting soooo old.
Yes, that sounds plausible.
Great!