Using "Version 20.2.0.175/Build 175.1842".
I use nls_date_format = 'DD.MM.YYYY HH24:MI:SS'.
When exporting to xlsx, the time information in MS-Excel is gone and the date-format shown is "MM.DD.YY" (the time information is not hidden by the cell-format, but is really missing!)
e.g. SQLDeveloper: "31.01.2021 13:41:59" => MS-Excel: "01.31.2021"
As I was not able to solve this issue, I copied " Version 20.4.1.407/Build 407.0006" in parallel without migrating the config from my 10.2 version.
I use the same nls_date_format = 'DD.MM.YYYY HH24:MI:SS'.
When exporting "31.01.2021 13:41:59" to xlsx, I see "1.31.2021 1:41 PM" in MS-Excel (seconds are there, but only hidden by the cell-format).
=> is the date/time-format used in xlsx-export a configuration/setting in SQLDeveloper or fixed in the respective SQLDeveloper version?