Failed to parse time string

Hi - trying to save a page and am getting a server error:

Server Error

Sorry, something went terribly wrong!

0 - An exception has been thrown during the rendering of a template ("Failed to parse time string (13/01/2025) at position 0 (1): Unexpected character")

The header of the page is:

---

publish_date: 10/07/2023
title: 'JaniKing Cricket Beano'
author: 'Don Robertson'
body_classes: 'header-lite fullwidth blogstyling'
taxonomy:
category:

• blog
  tag:
• NZervio

• 'Building Maintenance'
  media_order: highcleaning.jpg
  date: 10/07/2023

The date format in the user/config/system.yaml file is

dateformat:
default: d/m/Y
short: 'jS M Y'
long: 'F jS \a\t g:ia'

I've had this problem before and don't recall what I did - I think I modified the theme to ignore the system date formats, but I'd like a decent fix if possible.

Also - clearing the cache doesn't help. If I edit the md file and change the title, refresh the cache and then try to edit the page in Admin, I see the changed title, but still get the error - even though the date in the error message (today's date) isn't in the md file.

The page displays as expected. Other pages with the same dates in the header file - in fact I copied the header section from one page to another - can be edited.

But I can't see the Date 13/01/2025 in the Page-Header. Is it somewhere else?

Okay - if I save a date in the editing page as 10/01/2025, it saves, but the date gets changed to 01/10/2025. It gets displayed on the page as 10 January 2025.

If I enter the date - using the date picker - 15/01/2025, it errors. If I manually try to enter 01/15/2025, it won't let me - the date changes back to what it was.

Changing the page date format to d-m-Y H:i, it is fine. If I use a custom date/time format - eg d/m/Y H:i, it defaults back to m-d-Y. And then errors for days after the 12th of the month. d/m/Y is a pretty common format.

Also - to get rid of the error, you need to go to the Dashboard and then clear the tmp cache. Clearing ALL or using the icon at the top of the side bar doesn't work.