There are 24 hours in a day. We have no real discretion with roughly 12 of those hours. We need to eat, sleep, and do a few other necessary chores in order to maintain our existence. That hasn't changed much through the centuries, so far.

That leaves approximately 12 hours a day where we, as individuals, do have some discretion. That includes work time, play time, and family time.

Of those 12 hours, about 75%, or 9 hours, will be spent totally differently a few years from now than they were spent just a few years ago. Not everything will change, but 75% of life is in the process of changing right now.

The same kind of change occurred between 1900 and 1920 as well. Frederick Allen called it "the big change" in his 1952 book by the same title.(1) We call it a nine shift.

What this means is that nine hours in your day will be spent entirely differently in 2020 than they were spent in 2000. That is an enormous change. That is a nine shift.