Conversion date yyyymmdd en dd/mm/yyyy

Hi JC
??? I can't make your suggestion work in the requested case, that is, going from English to French
it works well, for example, from 12/04/2018 to 20180412 but with:
=E2;"aaaammjj") and still, without digitizing the result, which doesn’t seem possible

but in the other direction, your formula returns #VALUE for me
Best regards

Hello Vaucluse

I can't get your suggestion to work
and yet you handle dates well!
Of course it is necessary that 20180412 was entered as a date not as a number, that is to say the value 43202 (12/4/18) and not the number 20180412 which exceeds Excel's date capacity ;-)

Have a good evening.

Ok, it works, but GB, if the date is indeed entered as an Excel value in the format yyyymmdd, why complicate things with a reference and a formula, when you can simply change the cell format to DD/MM/YYYY
for example, for today
it would be 43250 in Excel which gives 30/05/2018 in dd/mm/yyyy and 20180530 in the yyyymmdd format
no, or am I mistaken?
Best regards and have a good evening

But of course, you are absolutely right, and to "convert the format" as requested, you just need to change it but the cell must be a date as was mentioned: “Elementary, my dear Watson”

@jc80: you don’t need your column and formula because you just need to change the format since your dates are correct.

@Alain, all you have to do now is tell us if your dates are dates or numbers.

Hello everyone,
The dates are recorded as numbers 20180531, there is no date in this format. The number is therefore not recognized and cannot be converted into another date format.
But the first answer from Vaucluse works well for me, I just wish to get the result in the same cell.
A1: 20180531 plus formula gives A1 = 31/05/2018
I can do it in two steps, putting the formula in B1 then replacing A1 with B1 (easier).
In any case, thank you all for your help
I'll come back if it doesn't work!