Or is there any other day better ?

If you also have a link or info with public daily travel cards it would be useful.

If you are spending a night over in a hotel, they provide a free transport card.

Lausanne tourism website

Lausanne Mobilis tickets

Or get a Gemeinde Tageskarte ( Carte journalière commune ) and travel around for less than CHF40 TO Lausanne and back home.

Not if you plan on shopping, whether it be supermarkets or non-food stores.

From Geneva you could take a boat to Lausanne, and come back on the train.

Depart Geneva Mont-Blanc CGN Sunday 10:15


Arrive Lausanne Ouchy Sunday 13:30

http://fahrplan.sbb.ch/bin/traininfo...ation_type=dep

Lausanne is much more lively on a Saturday. Main museums are open on Sunday though, if that's what you like.

I think, with Lausanne, every day is a Sunday.