Yes. Backdating is fully supported — you can create a booking for a show that has already happened, and contracts and invoices generate on it exactly as they do on a future booking.
This is what you want when you're catching up on paperwork, moving deals in from another system, or recording a show that was agreed verbally at the time.
How to do it
Click Create New Booking.
Navigate back in the calendar to the date you need. There's no cut-off preventing you from going backwards.
Select the past date and build the booking as normal — artist, buyer, venue, terms.
Save the booking.
Generate contracts, offers and invoices from the booking's own tabs. They work the same way as on any other booking.
Good to know
Settlement works on a backdated booking too, but it needs the ticket actuals entered and marked final before it will calculate. If you're recording a past show for the numbers, enter the actuals while you're there.
A backdated booking appears in reports for the period of the show date, not the date you created it. That's usually what you want, but it does mean a report you already ran for that period will change if you run it again.
If the show has been settled and paid outside Gigwell, you can still record it — enter the terms as they were agreed and record the payment against the invoice so the history is complete.