You have the possibility to lock tasks, projects and customers for further editing. For this you set the date of the lock-up. Before this date no further entries or changes of existing entries can be made.
To lock one ore more tasks go to "Reports/Project Time" and click on "Lock Task(s)".
You can now choose which tasks you want to lock and set the date of the lock-up. It's possible to lock only specific tasks or all of them at once.
The date of the lock-up will be displayed in the task properties (Edit Task) in "Administration/Tasks".
Here you can also take back the lock-up. For this click on the "X" next to the set date and then go to "Save".