Find Syntax

[Drew Tomlinson]

I'm trying to find all files with a modification time older than three 
weeks ago.  In reading the find man page and searching Google, it seems 
the time returned by 'ls -l' is mtime.  Thus I construct the following 
command:

find . -not \( -newermt 3w \) -exec ls -l {} \;

But it returns files that are newer:

-rw-------  1 nobody  nobody  35292 Dec 29 08:43 totContactedRcvdPeers.rrd
-rw-------  1 nobody  nobody  35292 Dec 29 08:43 totContactedSentPeers.rrd
-rw-------  1 nobody  nobody  35292 Dec 29 08:33 
./dc0/hosts/207/106/6/90/pktSent.rrd

I've tried various placement of the '-not' and the )'s but I can't get 
it right.  What am I missing?

Thanks,

Drew