If you want other default ranges different from weekly, you need to go:

* In the menu `Configuration` -> `Settings` -> **Timesheet Options**,
  and select in **Timesheet Sheet Range** the default range you want.
* When you have a weekly range you can also specify the **Week Start Day**.

To change who reviews submitted sheets, go to *Configuration > Settings > Timesheet Options*
and configure **Timesheet Sheet Review Policy** accordingly.

For adding more review policies, look at the *hr_timesheet_sheet_policy_xxx*
extra modules.