Those of you whose work involves precisely tracking your working hours in order to bill clients, what software do you use to record that data? Do you use just a spreadsheet or a more advanced system that allows your superiors to monitor and analyze your time? I am interested in installing a system like the latter to track my subcontractors, analyze trends, build reports, generate invoices, etc. Is there a name for this genre of software (e.g. CRM, supply chain, ERP)?