Custom en date formats interfere with en-GB language

[cdubz]

@cdubz Thanks for trying to get #321 sorted.

I've had a quick test of the latest commit (fae764a) and it wasn't fully working for me. (This should probably be moved to an issue)

Data input is working correctly and the input controls use the correct format, but the display list pages are not.
Not sure if this is expected or not (from a tech perspective), but the default time format when en-GB is selected remains 12h not 24h.

It seems that Timeline and Children are displaying correctly, but the following are not:

Notes
Temperature
Weight
All of the Activity list views.
Timer list view.

The odd thing was Timer (detailed view) was showing the date correctly (albeit with the default 12h time format), but when switching using USE_24_HOUR_TIME_FORMAT=True the time format was correct but not the date.

I was using python 3.8.12 if that makes any difference.

Originally posted by @Amith211 in #321 (comment)

[cdubz]

@Amith211 I got too focused on making sure the date inputs work and forgot that the formats for date strings are still applied to any en language. So this all kind of makes sense based on the solution I came up with. Now I’m just really not sure how to address this with Django’s date format system…