Converting Dates from Excel American to English

Hi all

I get a column of dates from an Excel sheet


They seem to change to the american format when the date is the 1st to the 12th - so in the example here it goes from the 31st Aug (correct) to the 1st Sept which is incorrect as it looks like the 9th Jan

Is there code I can write to check the dates and convert the ones which get converted in to the american format of mm/dd (I assume it happens between the 1st and 12th due to 12 months?) so they are all in the UK format of dd/mm?

Thanks for the help in advance

Thanks for the