Thanks for Zoho Invoice - really sweet app, a joy to use.

Is there a way to mark a timesheet log entry as "billed"? I started a new project about a month ago, and used Zoho for invoicing. Now that I see Zoho does timesheets as well, I'd like to move all my timesheets into Zoho. 

But when I add all my time logs for the last month, the log entries as say "unbilled", even though I've already invoiced the client through Zoho.

Is there a way to tell Zoho, "Hey, these timesheet log entries are already bill and paid"? I don't find any option like this in the UI.