Brevity will only generate claims for completed shifts. There are two several ways to complete shifts within Brevity depending on your needs.
The first is to simply mark as complete, while the other is by approving Timesheets for the related shift (recommended).
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You can then approve the timesheets in bulk by going to Employee > Employee Shift, selecting the appropriate records, and clicking the Bulk Complete button.
You can also use the Employees > Approve Timesheets function for approving timesheets.