Last-modified timestamp

[stephenng at alum.mit.edustephenng]

When I check out a file, I would like to restore the original
timestamp of the file--not the timestamp of when the changelist is
submitted, but the timestamp of when the file was last edited. 

(I've read through the previous timestamp thread.  Don't ask me why I 
need to do this!  It's for compatibility with another SCM system that 
we are transitioning from.)

I'm willing to use "touch" in a perl script to do this, but it seems 
as if the timestamp I want isn't even maintained by perforce.  

Is there a way I can find out what this timestamp is (it needs to be 
both the date and time, not just the time).