In fairness he says 90 minutes after waking, not 90 minutes after the walk. If you get home from the walk by 6:30 that's 30 minutes to make it, or potentially buy it if you have one nearby to get on the way home/quickly drive to.

Now yes that's already 10am, but considering he mentions 2pm in the right column, you could make the argument the left column is the "until 10am" part, and the right is "after 10am" part, though I am giving large amounts of benefit of the doubt at this point.