According to Michel Thomas, the original French word for today was 'hui' but as it sounded identical to 'oui' it was modified. It now is a mash-up of several words which literally translates to "in the day of today."
The discussion has moved to whether the English translation is correct. I need a fuller explanation of the "nous somme" construction and whether it's equally correct to say "Est aujourd'hui samedi ou dimanche?" (google translate gives the latter).