Locking Actual Hours / Locking Your Hoursheet
You can lock your own timesheet in the Timesheet view by hovering over the desired date and clicking the lock icon:
Clicking the lock icon prohibits you from registering actual hours for any project until the selected date:
As you click Accept, the fields before the chosen date are greyed out and can you can no longer edit them:
You can also lock hours on a project or task level from the Project's Dashboard; see the project Bridges #2 and task Project Management Duties in the screenshot above for example.
Only admins of Silverbucket can re-open locked dates for other users. This can be done by clicking the lock icon on someone else's Timesheet
Admins of Silverbucket can also lock other people's Timesheets in a similar manner after choosing the desired user from User dropdown list.