Fee Schedules apply to future time entries and adding a fee schedule to a project doesn't retroactively update its existing time entries. You can change the rates on existing or older time entries using the Update Rates option in the Time Entries screen. It applies the fee schedule rates, if available, or else follow the rate hierarchy (employee rates or activity rates). You can also update the rates from the Time & Expense Reviewer or Time Entries screen. Check CORE Help Center for details.