Ok, I'm not disputing any of what you state other than how Excel handles dates,
OR how date formats work. So here's an exercise you can do to see what I'm
saying:

Select A1:A3
While selected, key Ctrl+; followed by Ctrl+Enter
Today's date appears in numeric form 05/05/2018

Select A2 and set a Date format "14-Mar" in the Date NumberFormat list
Today's date appears in textual form 05-May

Select A3 and set its format to Text
Today's DateSerial appears 43225

Select A1:A2, type 43225 and key Ctrl+Enter
The display of A1:A2 doesn't change

Now we'll look at the system date format:
Select A1:A2
Since m/d are identical, type 5/6 then Ctrl+Enter and watch what happens. Now
type 6/5 then Ctrl+Enter into those cells. Now you see the system format for
dates displayed normally in A1 but without any ambiguity in A2.

So then, when dates are imported/pasted into cells, Excel reads the DateSerial
and renders that in the system format. Now since the numeric display has been
ambiguous to many since Vista, my solution has been to use textual formatting
instead. (That's all I'm saying) So when I design spreadsheets I deliberately
use textual date formats so there's no ambiguity (as expressed by the OP in
this thread) as to what the date is!

--
Garry

Free usenet access at http://www.eternal-september.org
Classic VB Users Regroup!
comp.lang.basic.visual.misc
microsoft.public.vb.general.discussion