Upgrade format issues

I’ve recently updated my pc from win 7 to win 10.
As a result LibreOffice has updated from version 4.? to I now have the problem that all the date formatting on all my calc spread sheets has changed. I’ve tried to change it on the language settings but it does nothing. Previously my dates we formatted as 31/12/1999 now they are 12/31/99. If i highlight the date column and format it as date 31/12/1999 it will change the date to 31/12/99. Also when inputting dates the previous version allowed me to just input 31-12 and it would auto change it to the full date as in my settings. this version does not do that.

Is there a way to put my settings back to how they were in version 4 or do i need to reinstall the old version which i think was much more user friendly.
Also can i turn off the blue highlights on the toolbar? My eye keeps getting drawn to them which is really annoying.
Sorry for the rant but I’ve got hundreds of spreadsheets that i will need to change manually,

As a result LibreOffice has updated from version 4.? to

Supposedly that means that you had updated it, because LibreOffice does not update itself automatically on any OS upgrades.

First, I’m a newbee, so take this with a grain of Salt…

uh… maybe your LOCALE was set to something else in the old version?
i’m taking a stab at this because i’ve seen (european) use of DD/MM/YYYY
as opposed to us USA people who are used to MM/DD/YYYY

and I’m thinking the Locale setting may be able to be set to resolve this.
Sorry, but i don’t know what you would set it to.

I’m thinking your fresh install set locale to USA-English, and it was something else in the old version??

location is ok - set as UK as was the previous install.

Please edit your question or add a comment.