The XBMC Library Updater will update your music and/or video libraries according to times specified by you. 

Thanks to pkscuot for several small tweaks to this addon!

General Settings: 

Startup Delay - if an update should run on startup (dependant on the time the last update has ran) this will delay it from running for a few minutes to allow other XBMC process to function. 
Show Notifications - shows notifications when the updater will run again
Run During Playback - should the addon run when you are playing media

Update video - updates video library
update music - updates music library
Video path - updates a specific video path. DISCLAIMER - the path you select must already be in the video database and have content selected. The path must also match your source path exactly. 

Timer Options: 

Standard Timer - specify an interval to run the library update process. It will be launched every X hours within the interval unless on of the conditions specified by you as been met (don't run during media playback, etc) in which case it will be run at the next earliest convenience. 

Advanced Timer - specify a cron expression to use as an interval for the update process. By default the expression will run at the top of every hour. More advanced expressions can be configured such as: 

    .--------------- minute (0 - 59)
    |   .------------ hour (0 - 23)
    |   |   .--------- day of month (1 - 31)
    |   |   |   .------ month (1 - 12) or Jan, Feb ... Dec
    |   |   |   |  .---- day of week (0 - 6) or Sun(0 or 7), Mon(1) ... Sat(6)
    V   V   V   V  V
    *   *   *   *  *
Example:
	0 */5 ** 1-5 - runs update every five hours Monday - Friday
	0,15,30,45 0,15-18 * * * - runs update every quarter hour during midnight hour and 3pm-6pm


Read up on cron (http://en.wikipedia.org/wiki/Cron) for more information on how to create these expressions

Cleaning the Library:

Cleaning the Music/Video Libraries is not enabled by default. If you choose to do this you can select from a few options to try and reduce the likelyhood that a DB clean wile hose your database.

Library to Clean - You can clean your video library, music library, or both.

Verify Sources Before Clean - this will verify all of your media paths (music or video) before running a clean operation. If any of these paths are inaccessible the clean operation will not continue and an error will be logged

Prompt User Before Cleaning - you must confirm that you want to clean the library before it will happen. Really only useful for "After Update" as a condition. 

Frequency - There are several frequency options. "After Update" will run a clean immediately following a scan on the selected library. The Day/Week/Month options will schedule a clean task to happen. Cleaning the Video Library is hardcoded for midnight and the music library at 2am. Weekly updates occur on Sunday and Monthly updates occur on the first of each month - these values are hardcoded. You can also choose to enter a custom cron timer for video and music library cleaning. These work the same as any of the other cron timers for the other schedules.