Automated profile switching is something that I used to love on the Symbian S60 3rd Ed OS. I used third party apps to implement it and it worked really well. I always said that this was a feature that ALL phones should have as standard and Bless Nokia they did decide to implement it on some phones but then didn't on others.
Here is an Application by Juha Riihimaki that activates profiles automatically based on time settings or calendar events. Also provides singleshot profile activation for a specified duration. So if you need it then click on the link below.
Source Ovi Store