Is there a way to add timesheet for a user before the actual date they were enabled? We disabled a user, he came back last week but was 'enabled' today. There is no timesheet for last week and I can't see a way of adding one.
To answer your question, No it is not possible to add a timesheet before the start date of the employee. If the employee has started working before the added start date in the user profile, then you will have to change the start date, login as that user and generate a timesheet.