A timesheet (or time sheet) is a method for recording the amount of a worker's time spent on each job. Traditionally a sheet of paper with the data arranged in tabular format, a timesheet is now often a digital document or spreadsheet. The time cards stamped by time clocks can serve as a timesheet or provide the data to fill one. These, too, are now often digital. Timesheets came into use in the 19th century as time books.