I don't know what tzaman was saying exactly, but what I noticed was that "today" got down to one or two pixels pretty fast, while the larger and larger time per

I don't know what tzaman was saying exactly, but what I noticed was that "today" got down to one or two pixels pretty fast, while the larger and larger time periods were restricted to only another ~1000 pixels or so, so at some point you have to shift back to imagining the relative lengths of time in your head again, instead of seeing e.g. "today" as 1/30 of the month.