That is a good plan for the upcoming pandemic or even a natural calamity. Even me i would do the same because we never know when will be the next calamity or pandemic will occur. Based on your plan I think 30 days stocking would be good enough to sustain your needs in times of calamities. We really must think and plan ahead of time before something serious calamity might occur.
The problem is that everyone doesn't know when the next natural disaster will come, because nature never gives an alarm when it wants to show disaster to everyone. However, I also think that it is wise to make food stocks once a month because that is the ideal duration of stocks for everyone and it's also not that long before we make more new food stocks in the next month. Because making food stocks is not solely for the purpose of natural disasters, but more for saving in the lives of each of us.