TCC was parsing the requested time correctly; however an RTL function was doing a "sanity check" and deciding that anything > 1000 should be set back to 10. I've changed the RTL source for the next build. (Though I'm unclear *why* anybody would want to set a timeout of a few weeks (or years).
Well, here's the justification. I'm doing my own sanity check on some files that come from a remote location - daily. On rare occasions the remote location has a problem where the files are not produced and therefore do not show up on my machine. I wanted a popup to get my attention if necessary each morning, but didn't want a screen full of them if I were out for a week or longer. So I though an 8 hour timeout would suffice :-)
I guess I could just have task scheduler kill the process if it runs for more than 8 hours and accomplish the same thing.