A short calculation:

The battery should last 10 days of idle time, that is 240 hours. In my testing it can last 3 hours of playing video over wifi with high brightness (probably as much power draw as possible). I measured 20 seconds for shutdown and one minute for bootup.

All thah data comes up to: off/on eats about 0.75% of the battery which is equivalent to about 2 hours of idle time.

While two hours might sound a lot, it is less then the sleep period of almost all human beings.