When does an updated cost or bill rate become effective?
The new cost rate or bill rate of time entries becomes effective after the update has been made. If you have previously entered time entries that have not been billed yet, you can update those entries to the new rates on the Time Entries or Time & Expense Reviewer screen using the Update Rates option from the Action menu. Enter the new rates manually or enable the Use current rate option. Check CORE Help Center for details.