All of which is a reminder of how odd it is that we think of time using spatial metaphors at all – indeed, that it seems virtually impossible not to. Ask me about the coming month and I can’t help picturing a sequence of little boxes, like a calendar; ask me what I did yesterday and my eyes shoot upwards, as I consult a “space” somewhere behind my head. Your specific images may not match mine, but anthropologists suggest that the basic metaphor – “time is space” – is a cultural universal. Which is a pity, in a way, because I’m pretty sure it makes our experience of time more anguished than it needs to be.
Mark Forster wrote in one of his books about "spaciousness" being a quality of life he valued. When talking of how we move through the day, "spaciousness" evokes a different feeling than "cramped."
As Burkeman says, time as space is a useful metaphor. Time is money, is another. An academic uses time the way a sculptor uses clay is another metaphor I've heard.
At this point in my development, metaphors are useful until they're not. They're fun to talk about and they can lead to insights sometimes, but it's useful also to know when to let them go. And to know that they're momentary thoughts.
"Time" does not really exist, the way trees and cars and physical bodies do. It's a concept humans have made up because it's useful to keep the trains running and we know when to celebrate birthdays, but time and its passing is a thought we create for ourselves. The way time can pass quickly or slowly to us -- and differently for someone else in the same circumstance -- is a clue that time is a thought we're paying attention to (or not) in the moment.
As the mystics tell us, there is no past and no future. There is only now. What happens to the time-management industrial complex when there is only now? As someone for whom time management has been my shadow religion for nearly 30 years, this is something I'm pondering quite a bit.