You can edit and re-submit a time off entry in Web TimeSheet, after it has been exported to Outlook. Once an edited booking is approved, you can re-export it. However, any time off entry that is re-exported into Outlook will not replace the existing, corresponding appointment; the outdated appointment will continue to exist in Outlook and you will have to delete it manually.

Note:
While the edited timeoff entry is awaiting approval, it cannot be exported.
A timeoff exported to Outlook, is not affected, when changes are made to the corresponding timeoff in the Web TimeSheet.