My esseu is , i dont a connection to the server only one day in the week. 

so, it must be to create a module that will update the databe of the server and database of the post.

 Hi Benmansour Abdessamed,

W.r.t your query, I have gone through it and tried to replicate it. Few observations which I found are that :-

1) Yes, working with Odoo POS is possible in off-line mode only if your Internet connection gets lost during any session. In this case the browser cache stores the information until the internet connection restores.

2) But for the very first time Internet connection is always required to connect with the server in order to start with/load the data. In your case, if you restart your PC it means system is restarting hence Internet connection would be required as the data would load again from the beginning.

3)This is because Odoo has the capability to work off-line even if your Internet connection gets lost only if you are in the mid of any session and you need to continue with other orders as your customers might be waiting in queue for their orders to be processed. In this case the browser cache stores the information until the Internet connection restores.

Hope this helps

 Cheers!!

you should be able with the posbox (https://www.odoo.com/shop/product/point-of-sale-posbox-312)

but check with google, there're plenty of resources about that