Could someone explain me what exactly the meaning of this file and what circonstance should I have to use it ?
2- How to configure the dialplan and then the users accept only calls in hours 08:00 to 21:00 ifelse playback (message)
The same, when the call is coming on bank holiday, playback (message) directly
Please be specific about what you don’t understand. A forum like this is not the place to get rewrites of documentation most people who need it manage to understand.