Mac OS 8 Developer Documentation
Operating System Services
The Time Manager allows applications and other software to schedule routines for execution at a later time. It provides a hardware-independent method of performing time-related tasks.
Inside Macintosh: Processes
(Chapter 3 - Time Manager)
This document describes the parts of the Macintosh system software that allow you to manage processes and tasks.
describes how to use the Time Manager and includes an overview, a tutorial, and a complete API reference.
Mac OS X