The Region setting within an AGOL organisation is very helpful, but it would be significantly better if services that are published or hosted in the organisation have date fields honour the display settings by default. This is honoured in the desktop applications that publish the services but not in the AGOL system. Or even better would be to add another setting to allow an Organisation to set the default date display format specifically. I know some organisations would want a Julian date format instead of a regional setting.
Basically each time I create a service or hosted feature layer I have to go through and change the display settings for every date field to reflect our regional date standard. This is very tedious and time consuming to say the least especially when you have multiple dates in multiple layers.