The source data includes columns for Name and Month Number, ranging from 1 to 12. Our objective is to change the column name from Month Number to Month Name.

In this post, I will illustrate two methods.

Method-1:

let

 Source = Excel.CurrentWorkbook(){[Name="data"]}[Content],

 Result = Table.TransformColumnNames(Source, (f) => if Text.Length(f) > 2 then f else Date.ToText(#date(2025, Number.From(f),1),"MMM"))

in

 Result

Method-2:

let

 Source = Excel.CurrentWorkbook(){[Name="data"]}[Content],

 ColNames = List.Transform(List.Skip(Table.ColumnNames(Source)), (f) => { f, Text.Start(Date.MonthName(#date(2025, Number.From(f),1)),3) }),

 Result = Table.RenameColumns(Source,ColNames)

in

 Result