Can Resources submit a Timesheet with zero hours or no rows of data?
Yes. The submission of a Timesheet with no rows of data should not be a problem if you are not using a process workflow.
If you are using the Time Approval Process Workflow, you may encounter some issues that can be worked out.
If you use the 'stock' Time Approval Process Workflow unmodified, the process will get stuck on the Action Item step when it tries to send an action item to a manager for approval.
Since there are no tasks for which the application can determine the manager, the step will fail.
However, through the application, you can re-assign the step to someone that can approve the Timesheet.
Another alternative is to modify the definition of the Time Approval Process Workflow.
You can modify the definition to see if the Timesheet has zero hours and automatically set the status to 'Approved'.
If you need assistance in modifying a process definition, please consult the product documentation or engage with the CA Technologies Services.