Non-Billable Task:
Non billablr tasks can be created by Admin. Navigate: from main menu click on "System Config ---> Non-Billable Task". You can view added task in non-billable task section in daysheet
By clicking on you can create new Non-billable task. You can view added non-billable task in the list of non-billable task.
Edit / Delete the non-billable task from view page as shown in below: