A simple Excel function to convert a digit to a month name
The first letter of the month (Eg: "N" of "November" for 9)
=TEXT(DATE(2000,A1,1),"MMMMM")
The complete month name (Eg: "November" for 9)
=TEXT(DATE(2000,A1,1),"MMMM")
The abbreviation of the month name (Eg: "Nov" for 9)
=TEXT(DATE(2000,A1,1),"MMM")
Thank to this thread.