Get month name from date
Do you want to convert the date into a month name?
The TEXT function converts values to text using the number format that you provide. Note that the date is lost in the conversion: only the text for the month name remains.
Do you just want to display the month name?
If you only want to display a month name, you don't need a formula – you can use a custom number format to format the date directly. Select the date and navigate to Format cells (Ctrl + 1 or Cmd +1), then select Custom and enter one of these custom formats:
"mmm" // "Jan" "mmmm" // "January"
Excel will display only the month name, but it will leave the date value intact.
A more flexible way
For maximum flexibility, you create your own month names with the CHOOSE function like this:
Enter the month names you want to return (customized as desired) as values in CHOOSE, after the first argument, which is entered as MONTH(date). The MONTH function will extract a month number, and CHOOSE will use this number to return the nth value in the list. This works because MONTH returns a number 1-12 that corresponds to the month name.
CHOOSE is more work to set up, but it is also more flexible, since it allows you to map a date to any values you want (i.e. you can use values that are custom, abbreviated, not abbreviated, in a different language, etc.)