You can restrict the entry of time entries via the entry form for employees, so that recording is only possible via the time clock in the user account or via the time recording terminal.
You can also make changes to time entries subject to approval, or restrict entry to a time window, for example with the earliest start time, or restrict entering time in the past. You can also specify that certain employees may only start the time clock at the time recording terminal (and, if desired, only stop it there as well).
Read here how to change the settings for entry permissions for employees.