Running 12 month total with variable date periods

Hi All

I am trying to get a formula that does a running 12 month total for a series of date periods (up to 6 years so could include periods during a leap year).


Period Ending Value per period Running 12 month total
01/01/2020 1 1
08/01/2020 3 4
15/01/2020 5 9
16/01/2020 22 31
29/01/2020 1 32

As we reach a period ending date of 02/01/2021 then the period ending 01/01/2020 would drop out of the running 12 month total
The running 12 month total needs to be calculated for each period ending date.

Also exactly the same as above but also for a 52 week period

Many thanks in advance

Hi John and welcome to the forum,

There is a "Running Total" available in Pivot Tables. See the attached to see if that is what you need.
12 month running total PT.xlsx
There are many sites that help with this topic. Here is but one at:
https://www.pivot-table.com/2013/07/...%20next%20year.

See if this does what you want.

Formula:

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Looks ok apart from the last few dates. Can you check your calculations.

Ok, try this one:

Formula:

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Or try this one in C2 and copy down:

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Please try in C2 and copy down:

Formula:

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