It is easy to make a number of meals in an hour. As a matter of fact, many people expect to make a meal in an hour or less.
An analogy in knifemaking would be anywhere from 6 hours to 12 hours. It takes 10 hours for most decent 2 ton epoxies to set up properly, as an example. Heat treating cycles require multiple hours as well.
Now, if you are talking about flint knapping, that is a different story. I have seen nice flint knife blades knocked out in a bit more than an hour.
When you pop out an arbitrary figure, you should have some idea of the different possible criteria involved, just like on Iron Chef.
Best Regards,
STeven Garsson