You're perfectly right.
However, this menu is confusing, at least the way it is translated in French. For what I now understand is a frequency of once per day, the "Synchronisation" (synchronization) menu entry reads "Hier" (yesterday) while it would be much more understandable with "Tous les jours" (every day). For once every two days, it reads "Deux derniers jours" (latest two days) instead of "Tous les deux jours" (every other day). I guess it has been copied from the Amazon menu, where I understand it represents the number of days you want to fetch previous commands for.
The full menu should read:
- Désactivée
- Tous les jours
- Tous les deux jours
- Tous les quatre jours
- Toutes les semaines
- Toutes les deux semaines
- Tous les mois
And the menu title should be "Fréquence de synchronisation" (synchronization frequency) instead of just "Synchronisation" (synchronization).