The Invoice Timeline is a useful report that gives you a visual imagery of the invoices in a bar chart over the past year. It splits the invoices into paid and unpaid, with the amount of total invoice to the left and the month along the bottom of the page.
Here you can very easily look at historical data and see the performance of the practice over a 12 month period as well as seeing invoices that are paid and invoices that have not been paid yet. By hovering the mouse over each bar it gives you the value of the invoices in the month.
Below the bar chart is a list of the of the months with sub headings for how much of the months invoices are unpaid or paid and then the total amount invoiced for that month.