When setting the clock back, if your regular bedtime is 11pm, you would set it back to 10pm
before turning in--- voila! an extra hour of sleep.
When setting it forward, you are actually sleeping from your normal bed time 'til
the time you would normally get up.
At that point, you set it an hour forward.
What actually happens, in that instance,
is that your sleep period was normal, but your waking hours have been shortened by one hour.
I know, I know, cheap trick, buuuuttt...
If you value your sleep that much...