Heartbeat configuration can be found under System - Configuration - Heartbeats.

Heartsbeats are batch functions that can be run every hour, day, week, month, or year. The record simply describes how often it should run and what file and function should be run. When run the heartbeat system will track the last result recieved from the function, and each function also has the option to cancel a heartbeat if a serious error has occured. It tracks how many times it was run, when it was last run and what time will run next. The next run time is usually the same minute every hour, or hour every day and so on, but it can drift if it takes longer than a second to run the heartbeat. This can be used for just about anything.

Heartbeats are run from the backend process so that has to be setup and be active for heartbeats to function.

There are some heartbeats included with the TwoSpot distribution, but as the layout suggests it's primarily intended to be used for specific needs of each installation.

The included heartbeats cover currency updates, timers, some caching, checks, and clean up. Not all are enabled by default.