Sebastian Witte Aug 18, 2021:

60 working days as from the 10th or 25th day of the month after the date of invoice. This means that Days 1 to 9 of each month after the date of invoice are treated as Day 10 (A) and Days 10 to 24 after the date of invoice as Day 25 (B). Day 25 to the last day of the month after the date of invoice are treated as Day 10 (A) of the next month. Only A and B, respectively, are when the 60 working days start to run.