Using items to track billable time
You can enter your billable time as an item. In fact, you can create a different item for each type of billable time that you want to track. To do so, Use the Item Information window to create new items for each type of billable time activity that you want to track. Follow these steps to create each item: (Creating items)
When you create an invoice for your billable time, enter the number of time units and the appropriate item number. Feel free to override the default description. You can enter up to 255 characters in the Description field.