B, upon arriving home from work at 10:40 am one Saturday, asked:
B: What time did you get up today?
Me: I don't know. Maybe a mere half hour ago.
B: A half hour ago, huh. Are you sure?
Me: Yes, because the fake clock* said 10:20 a.m.
B: Ah ha! So you really got up 20 minutes ago!
Me: Um, no. A half hour ago. Just because the fake clock is ten minutes off, it doesn't mean that time moves any different.
Me: Are you following me?
Me: When the fake clock says 10:50 right now, it is really 10:40. So when I got up at 10:20 fake clock time, it was really 10:10 - a half hour ago.
B: Fake clock schmake clock.
...and B for the win! Really, how can you argue with a rhyme involving made up words?
*fake clock refers to our bedroom alarm clock that we set 10 minutes fast. Really, it is fake time not a fake clock.