Updates:
Status: WontFix
Comment #2 on issue 872 by pekka.klarck: Outputdir shall be timestamped
http://code.google.com/p/robotframework/issues/detail?id=872
There's already a command line option for setting the output
directory(-d/--outputdir) which makes both timestamping and indexing easy.
For example this works on Unix:
pybot --outputdir `date +%Y%d%m-%H%M%S` tests.txt
Above is obviously slightly more complicated than something like
pybot --timestampoutputdir tests.txt
but then again it gives full control on the timestamp (or index) format.
The reason we did implement --timestampoutputs option was that using it is
considerably easier than specifying the same timestamp for all output files
individually.