The 'Next Chase' & 'Last Chase' columns use the below format.
The 'Next Chase' column displays when the relevant invoice is due to be chased. For 'Next Chase' in an invoice row, the number preceding the date represents which number chase email this will be. The date is when the next chaser will be sent.
The 'Last Chase' column displays when the relevant invoice was chased last. For 'Last Chase' in an invoice row, the number preceding the date represents how many chase emails have been sent. The date is when the last chaser was sent out about that invoice.
In the customer name row, 'Next chase' & 'Last chase' will display the most recent (closest to the current date) last chase for that customer, and soonest (closest to the current date) next chase due to go out.
Hovering over the next and last chase for an invoice will display a preview of the chaser that is due (or has gone) out.