Datetimes display different to edit value

v.8.1.47
ACDT timezone UTC+10:30

I have no idea what's going on here and I haven't seen this before, but I have a DateTime memory tag set to a date. If I edit its value in the tag browser, double clicking on it to edit it then shows a completely different time (offset by -2:30). It's as if the display and edit values are in different timezones... Both gateway and designer are in the same OS timezone.

I am seeing the same thing with datetimes displayed in the datetime component in Perspective: the prop in the prop editor shows a different datetime than the one shown in the browser

Lol what?

Possibly related, I noticed this as well after saving...