Does Vista Wake Up for Defragmenting?

I did some googling for an answer to this, but did not find a direct answer.
My Disk Defragmenter is scheduled to run at 1:00 a.m. every Wednesday (the
default schedule that came with the installation). Normally my computer is
in Sleep mode at that time. Do I presume that the Defragmenter wakes the
computer, performs the Defrag, then puts the computer back to Sleep? The
reason I ask is that I see that the last Defrag was run last Wednesday at
10:11 p.m. which might have been about the time I put the computer to Sleep
for the night; so possibly it got it over with before it actually entered
Sleep? Just trying to understand. Thanks.

Hi John,

By default it should not wake your computer up on it's scheduled run and run as soon as possible instead. Usually not long after the next time you wake the system up. You can check in "Task Scheduler" (Administrative Tools) to see the settings for Defrag.

Hope this helps,
Shawn