Hi,
If you have the information in the layout of DIBO's post - dates in column A, values in column B. You could use this array formula (not in either column A or B which must only have data):
=SUM((A:A>=(MAX(A:A)-365))*(B:B))
You create an array formula by pressing: CTRL-SHIFT-ENTER together. If you have done it correctly the formula will appear in {} in the formula bar - ie:
{=SUM((A:A>=(MAX(A:A)-365))*(B:B))}
What this is doing is taking the largest date value in column A and deducting 365 to get the date a year ago and then using matrix multiplication to select all of the values which have dates that are newer.
HTh
EG
Last edited by ExGrunt; 5th Jun 2018 at 19:01.