Thanks for your responses.
I'm going to ask my client to produce at least once invoice per month for each client she sees during that month.
Each invoice produced will be dated the month the revenue is earned so the revenue will be recognized in the correct month.
It would have been better if the revenue was booked on the date specified on the line describing the service being performed on the invoice, but I guess this is too granular for QB Desktop. At least I can display the individual dates on the invoice even if the dates are not used for anything else.
