Options for nested Ifs

[Neag]

Hi... I have data for 40,000 customers (in rows) for 60 months(in column). Each column has three possible values 0,1,NA.

I want to check when 1 appears for first time each customer and then map the month in header of that column as output. I do not want to use nested if.

I am really only a beginner in excel, please help.

 

[pecoflyer]

Please post a sample sheet with some data and mocked-up expected results

 

[Peter Bartholomew]

It very much depends on the version of Excel you are using and even where you want to place the result.
The sort of formulas that may be useful include

= MINIFS(dateHdr, customerRecord, 1)

= XLOOKUP(1, customerRecord, dateHdr)

= INDEX( dateHdr, MATCH( 1, customerRecord, 0) )