^D. was pretty interested in the time today, as he's on a tight
  schedule with Halloween things tonight. Waiting is hard at any
  age, so getting a good 'feel' for a clock and wait time is
  important. We had a Q&A session and the best moments were: a)
  the lightbulb going on when he "really got" the 59 to 00 minutes
  thing when the hour jumps to the next one (because it matters to
  him - he leaves at 6:00) and b) Watching my cell phone's clock
  as it went from 4:59 to 5:00. Also got to show how "time flies
  when you're having fun" (jibjab took 13 minutes, q&a took 12
  minutes and it went fast, chutes + ladders went fast at 10
  minutes - BUT waiting that ONE MINUTE for the time to change
  from 4:59 to 5:00 felt SLOW. The nature of time always interests
  me, so it's great to pass a "sense of time" on.^