Hi

If you know the first & last file created at 6:29 & 21:30 use the below command.
find . -newer firstfile ! -newer lastfile -print -exec cp {} /directory_to_be_copied \;

Else touch a dummy file and delete it after doing copy.

touch 0605062909 dummyfile1 (MMDDHHMIYY)
touch 0605213009 dummyfile2

find . -newer dummyfile1 ! -newer dummyfile2 -print -exec cp {} /directory_to_be_copied \;