This is a smart move. It should be longer than four days but they are probably thinking people wouldn’t have enough food to last that long.
A smart attempt maybe. Don't see how it is expected to work.
Telling people that they must stay in their homes and just 'die' is more likely to ensure that they will go out on a major 'spree' of some kind. They figure they are going to die no matter what, so why obey the government ?