I've just tried clicking on "Death at event: " for a gentleman who died at the Battle of Pinkie Cleugh. All I did to the edit screen was click the "Julian" button to show that it was "Old Style". The system threw away most of the other carefully assembled facts. So I undid the edit while incorporating the new line that mentioned "Julian".
It needs fixing. One approach could be to have the calendar options as part of the standard form, hideable if possible. Another approach, not necessarily inconsistent with that, is to make the "Death at event" edit box perform the same way as the child box does: i.e. not affecting anything else on the page.
First thing to do should be to disable the invitation represented by the blue link style for "Death at event: " in the infobox until it is safe.
-- Robin Patterson (Talk) 12:32, September 25, 2013 (UTC)