options: --backup-dir and --sufix not combinable?

[Samuel Hug]

hi there

i would like to backup any file which is updated into a specific 
directory, "--backup-dir=" does work well. but i also would have 
multiple backups from each file, to make this possible i thought i 
combine "--backup-dir=" with the "--suffix" option and attach a 
timestamp to each files name.
well if i use "--suffix" alone it works, but in combination it won't 
work, it just overwrites the old file in the backup-dir.

is this intention?

best regards
sam