When client/matter is established, there is an option to set the matter to Hourly or Fixed Fee. If a matter is deemed hourly, every time entry has the option to be set as non-billable or no charge. See image one below. This function has two purposes. First, it allows you to track how much non-billable time is allocated to a specific client and/or matter. Second, you can show that time as non-billable to the client on the invoice.
The line item on the invoice will show the date and description but you $0.00 as the rate. This is illustrated in the second image below. This non-billable time can also be viewed in a timekeeper report.
Image One: Non-billable time function.
Image Two: Draft Invoice with non-billable time.
Image Three: Time Keeper Report