Running the Mac OS X maintenance scripts
Mac OS X is a UNIX-based system. UNIX systems run scheduled maintenance routines — known as maintenance scripts — to clean up a variety of System logs and temporary files. By default, these are executed between 03:15 and 05:30 hours local time, depending on the script.
If your Mac is shut down or in sleep mode during these hours, the maintenance scripts will not run.
This Dashboard Widget, Maintidget, will let you run the scripts when you choose.