[otrs] TimeAccounting

Hi I am in the process of assessing whether OTRS will be suitable for my needs. Some of the support we offer is included in our monthly fee. Other support is billed for on a per-minute basis. The TimeAccounting module appears (at least from the list archive messages) to be exactly what we need. So, my questions: 1. Do I need this module or is there something already in place that will give me access to timesheets? 2. Where do I find this module - can't find a download link or any reference to it anywhere I am using OTRS 2.2.6 Thanks Brendon