Ever since upgrading to MacOS 10.15.4 (with Safari 3.1), and also iOS 13.4, when I'm using Safari the dates in the DVR web site look like 25/02/2020 (instead of my usual 02/25/2020), and the times are in 24-hour format (used to be 12-hour).
When I use Chrome, the dates and times are both in my usual format. Also, the formats are as expected when using the app on iOS.
Seems like the new versions of Safari may have broken something?