During the hours that your office is closed for business you would want to switch off the auto-attendant, as to not waste clients' time with menu selection for unmanned departments.
Instead of the regular auto-attendant you would set an alternative one to play a simple message letting clients know the office working hours, and, if applicable, prompting them to leave a voicemail in a company wide mailbox.
The hours for the alternative auto-attendant can be customized manually to match the daily opening-closing hours of your company.
You can also turn on Holiday and Weekend Mode to automatically apply closing days schedule for the alternative auto-attendant based on a standard calendar. The mode is accessible for administrators via Telebroad's online interface, so you can activate it even if you are already on a holiday vacation from anywhere in the world.