This is part odf my code from a Excel VBA program. They are all Julian Dates
around 2451544.5 days. For some reason it does not like PupA = A - Pup. I
think it is the iterations (k+2) then (k+1). Any suggestions?

Dim P, A, Pup, Adown, AP, PupA, PAdown As Double
For k = 1 To n
P = .Cells(k + 2, 5)
A = .Cells(k + 2, 10)
Pup = .Cells(k + 1, 5)
Adown = .Cells(k + 3, 10)
AP = P - A
PAdown = Adown - P
PupA = A - Pup
.Cells(k + 2, 12) = AP
.Cells(k + 2, 13) = PupA
.Cells(k + 2, 14) = PAdown
Next k