I've had this pain for years

My understanding is that Access can use the British date format if it can be unequivocally and correctly be converted to the US date format.  For instance, #28/3/2023# unequivocally means March 28th since there is no 28th month; so Access can interpret it as March 28th even in the US version of Access -- and, in fact, all international versions:

     Dlookup("OrderID", "OrderT", "Date=#28/3/2023#")
     Dlookup("OrderID", "OrderT", "Date=#28-3-2023#")
     Dlookup("OrderID", "OrderT", "Date=#28-03-23#")

If the name of the month is spelled out, such as "Mar" below, Access can also interpret the date unequivocally and correctly:
    
     Dlookup("OrderID", "OrderT", "Date=#28/Mar/2023#")
     Dlookup("OrderID", "OrderT", "Date=#28-March-2023#")
    

But if a date is #8/3/23#, which is equivocal in appearance to British and Americans, then Access will interpret it, by default, the American way: August 3rd, 2023.  

(What doesn't it interpret it in the British format by default?  Because Access is an American product.  This may sound facetious, but that's how things work sometimes.  If you invent something, you make the rules.  American websites use ".com" while other countries' websites have to use their country codes (.uk, .dk, .cn, etc.) because the US invented this naming system.  There are elements called "noble" elements on the periodic table because the British discovered them, with funding from royalty at the time.)

If a date is invalid, Access may take it upon itself and "correct" it to a different date from what you intended.  For instance, if you write #29/02/01#, intending it to be 29th February, 2001, Access will not interpet "29" as the day because there was no 29th in February that year.  It will, in fact, interpret "29" as the YEAR in the ISO date format, because that is the only way that makes sense to Access.  So your date will be "corrected" to February 1st, 2029!

Access also can't use non-English names for months.  Another poster alerted me to this in a recent thread:

https://599cd.com/blog/display-article.asp?ID=2553&CommentID=66083#StartOfComments

If you use "Maart", the Dutch name for March, in a date, Access will return an error:

     Dlookup("OrderID", "OrderT", "Date=#28/Maart/2023#")
    
Access does accept non-English month names in textbox entries and the query designer.  If you enter #28/Maart/2023# as the criteria in the query designer, the SQL view will immediately convert it to the US date format.

That's an interesting perspective Kevin. While I do agree with you, i think the issue isn't so much following the american guidelines but rather the consistancy. Maybe too clever.

The smart thing to do would be to follow the regional settings on the computer but to follow the american rules 100% wouldn't be too bad either. It's the auto correction I think which makes the job much harder.

Ironically, Rick recently released a video on Access' auto correction of percentage data entry - Percent Bug. In it he shows how access will interpret 0.5 as 0.5% BUT .5 is interpreted as 50% due to starting with a non-numeric digit. In the video, he basically says the same as I have done - Choose a method, any method, and stick to it. Being partial of one and partial of another is just asking for trouble IMHO.

Daily rant over! Appreciate the response. I'm in work now so gonna go back to sleep 😴😜

Hence why I switched to ISO dates