date/time format in Vivid

[Glenn Holmer]

I'm testing alpha 1 of Vivid. Where is the setting for date/time format?
In System Settings, I'm looking under "Regional Settings / Formats", but
"Detailed Settings" only brings up region selectors. Where do I set the
date and time format? I want the digital clock to show ISO 8601 date
(yyyy-mm-dd) and 24-hour time.

-- 
Glenn Holmer (Linux registered user #16682)
"After the vintage season came the aftermath -- and Cenbe."