Service Date is a new feature and by applying a Service Date to an Income or Expense Invoice or Credit Note, it allows the user to choose a budget period to apply that invoice or credit note to.
Service Date settings are found under Manage Companies in the Invoicing Section:
Service Date is defaulted to ON and can be switched to OFF for any Company. Applying a Service Date to an Income or Expense Invoice or Credit Note allows the user to choose a date for the invoice or credit note to be allocated in the budget. If Service Date is set to ON (default) at a Company level, then the Service Date field will show on all Income & Expense Invoices, Credit Notes and associated budget screens & reports.
If you do not enter a value into the Service Date field, then an Invoice will follow existing logic whereby an Income Invoice will fall into a budget based on Due Date and an Expense Invoice and Credit Note will fall into a budget based on Issue Date.
If the Service Date is set to OFF at a Company level, then the Service Date will not show on Income & Expense Invoices or Credit Notes.
Note that Service Date cannot be applied to Repeating Invoices.
Example Income Invoice showing Service Date: