Using what you know now in prior period updates - acceptable?

A procurement item is discovered to be taking 90 days longer than expected, you discovered this in March but you are updating February data.  You could and should revised that duration to add 90 cal. days, otherwise you are publishing knowingly wrong data.  Plus this did not happen in March - you don't when the equipment vendor started sand-bagging - probably from the start, so either way you should use the data you know now (not then) as correct for item?  correct? - it would be different if it were a work item that extended in March - and you found out in March.  Correct?