TimeMachineScheduler disables the automatic backup function of Time Machine and installs its own launchd agent. As the agent is located in the main library, the administrator password is required for all (writing) operations. Except disabling Time Machine no further system files and preferences will be touched by TimeMachineScheduler.
There are (still) some access privileges problems in OS X 10.5, if the operation system has been updated, migrated or installed with the archive & install option. TimeMachineScheduler takes care of all files and sets owner, group and the privileges to the proper default value.
You can install and uninstall the agent as well as only load and unload it to disable making backups temporarily. The interval can be set between 1 and 12 hours, and the agent can be set to run additionally at load, which means also at startup and login. You can press a button to run a backup immediately. The status of the scheduler will be displayed.