I believe that the 10 days of darkness will be a communications black-out while the military rounds up all the deep state scum. Only the military will have comms, satellite, internet, broadcast TV and phones. Normies will not even have GPS. Power and water will still work. POTUS will communicate via his Emergency Broadcast system. Its the only thing that will work. So no gas stations, grocery stores or pharmacies will be able to transact business except in cash.