IsNewerThan with fudge factor

[Martin, Jason H]

Hello, I am trying to have CFEngine determine in which order two files
were installed to determine if it should update it. Essentially, if the
file appeared before CFEngine was installed, then CFE should not update
it. If the file appeared after CFE was installed, then it should be
updated. IsNewerThan handles this pretty well by comparing a CFE binary
with the target file, except that I'd also like CFE to update the file
if both CFE and the file were installed within X hours of each other
regardless of order. This would handle the situation where both CFE and
the file were installed close together but out of order.  

Does anyone have any recommendations on how to accomplish this? The
target platforms are linux/hpux/solaris and perl isn't a given, so the
solution pretty much has to be based on the bare-bones tools available
on a UNIX os.

As far as CFE goes, it would be nice if it supported a IsNewerThenByX
function that took a fudge-factor as an argument.

Thank you,
-Jason Martin