54.17.1 Update the charge rate and charge amount in existing timesheets and disbursements all in one go based on a specific Rate Schedule
See Invoice -> Timesheet tab (or Disbursement tab) -> on the bottom-left click the "Bulk Update Charge" button
Select the Rate Schedule to use
Enter the Date range
Check or uncheck to include or exclude disbursements
Select where to apply new rates to: All, Allocated Timesheets only, Unallocated Timesheets only