O legal de usar "tar" para fazer backup (e também restaurar) é que vc consegue manter a data de criação do arquivo. Olhando em meu laptop, achei alguns beeeem antigos:
-rwxr-xr-x 1 helio users 181 Dec 12 2003 speedyteste.sh
-rwxr-xr-x 1 helio users 67 Nov 18 2003 coreclean.sh
-rwxr-xr-x 1 helio users 350 Sep 24 2003 mywget
-rwxr-xr-x 1 helio users 1908 Sep 23 2003 jisql
-rwxr-xr-x 1 helio users 282 Jun 16 2003 dvd-rip_pt.sh
-rwxr-xr-x 1 helio users 5380 Jun 3 2003 tcp_queue_test
-rw-r--r-- 1 helio users 4458 Jun 3 2003 tcp_queue_test.c
-rwxr-xr-x 1 helio users 111 May 27 2003 xquake2.sh
-rwxr-xr-x 1 helio users 1091 May 20 2003 change_bg.py
-rwxr-xr-x 1 helio users 1063 Apr 27 2003 make_downloads.py
-rwxr-xr-x 1 helio users 629 Apr 21 2003 avi_enconder.sh
-rwxr-xr-x 1 helio users 242 Apr 21 2003 dvd-rip.sh
-rwxr-xr-x 1 helio users 7887 Apr 21 2003 dvd2divxscript.pl
-rwxr-xr-x 1 helio users 51 Apr 3 2003 mygcc
-rwxr-xr-x 1 helio users 111 Mar 25 2003 hgcc.sh
-rwxr-xr-x 1 helio users 1017 Feb 25 2003 pimpoplayer.py
-rwxr-xr-x 1 helio users 653 Dec 11 2002 pythonget.py
-rwxr-xr-x 1 helio users 2814 Nov 21 2002 aph_preenche.py
-rwxr-xr-x 1 helio users 809 Nov 19 2002 get_storeproc.sh
-rwxr-xr-x 1 helio users 377 Nov 19 2002 isql_safe
-rwxr-xr-x 1 helio users 480 Nov 13 2002 myisql
-rwxr-xr-x 1 helio users 647 Nov 1 2002 asse.sh
-rwxr-xr-x 1 helio users 20 Oct 2 2002 pfctl
-rwxr-xr-x 1 helio users 2519 Aug 14 2002 velox-auth.py
-rwx------ 1 helio users 13885 Aug 8 2002 stat.pl
-rwxr-xr-x 1 helio users 1700 Aug 1 2002 changepasswdial.py
-rwxr-xr-x 1 helio users 83 Jul 30 2002 evol-kill.sh
-rwxr-xr-x 1 helio users 2762 Jul 25 2002 http_teste.py
-rwxr-xr-x 1 helio users 115 Jul 3 2002 planta_dsl_teste.sh
-rwxr-xr-x 1 helio users 166 Apr 9 2002 bookmarksupdate.sh
-rwxr-xr-x 1 helio users 1805 Jul 17 2001 id-velox.sh
-rwxr-xr-x 1 helio users 123 Jun 18 2001 wordview.sh
-rwxr-xr-x 1 helio users 275 May 21 2001 Xterm
-rwxr-xr-x 1 helio users 261 May 21 2001 Xterm-ROOT
Devo ter alguns de 1997 em outro backup, do antigo servidor de casa :-)