View time-dependent

[Pelaton73]

Morning, I would like the view of the app to change based on the time.
The formula I had thought of: IF(TIMENOW()>(Addetti[Ora Servizio]+"008:00:00"),"Menu","In Turno"), gives me this error: Arithmetic expression '(Addetti[Ora Servizio]+"08:00:00")' has inputs of an invalid type 'Unknown'

Suggestions?