No. GASTROFIX runs for days without an internet connection. All important functions including X- and Z-Reports are also available offline. The only things that necessitate an active internet connection is the comfortable web access to master data and reports.
As soon as an internet connection is established, GASTROFIX automatically synchronizes itself with the cloud.
If you don't have an internet connection for several days, you can simply connect your master device to an alternative network after closing time to upload the data.