I meant both, but left it ambiguous to see which one people would pick.I think he meant mechanical watch maintenance.
I suspect most people won't have a clue how to power their digital watch via homemade batteries, nor would they know what to do if they opened up the back of their fully mechanical pocket watch. You can't just use any old oil, and if you use too much or get it in the wrong places you'll be left with a nonfunctional timepiece.
But I'm splitting hairs here. If we get to the point where I cannot buy a battery for my watch, knowing the date and time is hardly going to be my highest priority, and no doubt I'll learn how to use older techniques and methods quickly enough for the times I do need to understand date and time.