PowerPivot get last update

Question

My table looks like this:
FLIGHT | UPDATE | ETA | ARRIVAL
A | 2/6/14 | 6/18/14 | 6/16/14
A | 6/6/14 | 6/19/14 | 6/16/14
B | 1/7/14 | 6/2/14 | 6/26/14
B | 6/16/14 | 7/2/14 | 6/26/14
B | 6/23/14 | 6/26/14 | 6/26/14
I need to get the latest ETA update 7 days prior arrival. For instance: Flight A arrived on 6/16. 7 days before this was 6/9. The latest update before this date was 6/6. On that date, the provided ETA was 6/19. So my measure would return:
A -> 6/19/2014
B -> 7/2/2014
How would you write this in PowerPivot?
Thanks

Answer 1

You'll need to add a working day flag to your data, either in a date table related to [UPDATE] or in the fact table itself. Then modify the last bit of the formula (before all the closing parentheses) to this:
ALL ( '--tablename--'[UPDATE] ),
                    '--tablename--'[UPDATE]
                        < VALUES ( '--tablename--'[ARRIVAL]
) - 7 && '--tablename--'[WorkingDayFlag] = 1