The Units you enter in an activity slip appear as Hours in a timesheet. The Hours you enter in a timesheet appear as Units in an activity.

If you marked the I Use Timesheets... preference in the System view of the Preferences window and selected Time Billing and Payroll as your use of Timesheets:

• The units you've entered in any activity slip for this employee appear automatically in the timesheet's corresponding payroll category row and day column. The billing units that are used when you enter activity slips (you define a unit as 1, 6, 10 12, 15 or 30 minutes in the System view of the Preferences window) translate to hours (0.00) in the Timesheet.
  
  -- and conversely --

• Entries you make in the daily columns for any row in which you selected an activity automatically create activity slips. The hours you enter in the Timesheet translate to billing units in the activity slip.