This is an event that is kicked off nightly for each invoice.

This event only occurs for unpaid/overdue invoices. Voided or paid invoices will not fire this event.

Internally, this event is used for updating caches, consistency checks, scheduled events for invoices, etc.
Externally, you can choose to hook into this event and use it for whatever you would like.

Note these fields:

• context_str = invoice
• context_id = ... (this will be the invoice_id of the invoice)
• event = nightly