find a file based on date timestamp

find . -type f -newer guidedog | xargs -i mv {} going2dogs

With the above command, we are
1) looking for files (type -f) with date and timestamp newer than file guidedog.
2) then moving those files to directory going2dogs

guidedog is a dummy file which has the reference time we need. It can be created as -
touch -t 200911251340 guidedog

So all the files that were created after 1:40 PM on 11/25/2009 will move to directory doing2dogs.

Also, between two timestamps will work as

find . -type f -newer guidedog -a ! -newer anotherguidedog | xargs -i mv {} going2dogs

Update : Above command will move anotherguidedog also. To avoid that additional condition should be added before passing output to xargs:
-a ! -name anotherguidedog