Now let's go through a backward pass calculations. And we'll go one by one, similar to the backward pass calculations that we did for the activity on node. We do start with the last one and move backward. So we can have either the arrow here or here. So this is then day 15. And then, the late start date for the predecessors after this 15 would be the same thing. So here, you have 15, here, we have 15, and here, we have 15. So that being said, then the late start of an activity will be the late finish minus the duration. So for J, would be 15 minus 1 equal 14. For K, 15 minus 2 equal 13. For I, 15 minus 13 equal 12. As all the lead start dates for these activities. So let's go towards the node number 9. With node number 9, we take 14 in this time, towards this node here, which will go towards the predecessors of D and this dummy activity, which will go towards this node. So we have 14 here, 14 in this dummy activity, and 14 here. So once we have a node that has two activities coming, in this case, for node 8, coming J, and coming K. So that latest for node 8 would be the minimum between the 14 and the 13, which will be 13. And the 13 on node 8 will be equivalent to the late start dates for H. And this is a dummy activity would be also 13, 13, 13, which will be also for G13. And the late start dates for G and H will be 13 minus 5 equal to 8 here. And for H, 13 minus 3 equal to 10 here. So that node in time then will be in the backward pass calculations. The minimum between 8 or 10 which will equal to 8, And the 8 will be the late start of activity E, 8 minus 4, that I'm sorry, late finish. And the late start for E would be 8 minus 4 equal to 4. Because this is a dummy activity, we have 8 and 8 here. That will leave us to go to node number 6 down there. 12, we can take it also as 12 here, Which will leave us to late finish 12, late start 12, because it's a dummy activity for F. Late finish, 12. The late start, 12 minus 3 is 9. Because this is the only activity coming, the node time here is 9 in the backward pass calculations. And for node 3 here, we have the minimum between 8 and 12, which will be an 8 and we can have it above here. Which the late finish day for B would be also 8 in this case. 8 minus 2 equal 6, which will be the late start date for B, so what we missing here? Node 2 here, which we highlighted from D and E. D will be 14 minus 14 late start, late finish date for D minus 4. Late start date for D is 10, the minimum between 4 and 10 also equal 4, which will have the late finish 4, the late start, 1 for activity A. Then will leave us with 9 as a late start for C. 9 minus 1 is 8. The minimum for activity 1 between 1, 6, 8, which will be, 1 here. So that is the calculations that I did by hand to identify all the early start, early finish, late start and late finish of all the activities. And what's the point in time that we can reach that node and the latest point in time we reach that node.