I believe the latter is by intent and was intended to avoid dd/mm and mm/dd order confusions as the month is rendered in text. After saving the desired OS setting is restored.
When shown as a Key Attribute or in Get Info/attributes a Date-type attribute renders as follows (from aTbRef):
Date-type data. Shows the data and time, with the date/time format in the host OSâ short date format, so this will vary by the userâs locale and their choice of OS settings . Document Settings offer a small selection of variations on the OS format. An alternative date-time string format can be used for all Date-type attributes in KA by setting $KeyAttributeDateFormat at document or note level using a date format string. On entering a date, if no time is specified, the time element of the attribute value defaults to current system time. A date-picker control is offered to the left of the value box. When editing dates in the key attributes table, from v8.2.3 the date string is changed before editing to its value in normal format (medium date, short time). This avoids ambiguity in short dates, where the default US style uses 2-digit years: i.e. does 12/7/41 represent a date in 1941 or 2041?
Note the recent change in v8.2.3.
The formatting in this context has no effect on the storage of date-type data in a TBX (which I believe is unchanged).
Ah. As an Australian American working on a UK-US project, Iâm sensitive to the date issue, which is precisely why I had the date format set to quasi-Japanese (pure big-endian)! So the basic idea of editing in Medium is not stupid. You might however want to adjust the documentation to describe the actual behavior, which is that a double click gets you Medium and two (well-spaced) single clicks gets you Short. (Please donât take away the Short mode!)
Weâve had all sorts of recurring confusions that arise from the US propensity to use 2-digit years in short dates. For example, if you write 12/7/45, do you mean 1945 or 2045? Each may be âobviously correctâ to various users,
So, when editing, we temporarily switch to medium format and remove the ambiguity.
Thatâs a half truth - if you double-click on the field, you get that behavior, but if you click once, pause, and click again, you end up editing a Short Date version.
It was certainly confusing to stumble on, but now that I know whatâs going on I like having access to the Short Date editing and I hope they donât entirely take it away.