gnus-article-date-headers

gnus-article-date-headers is a variable defined in `gnus-art.el'.
Its value is

(combined-lapsed)

Documentation:
A list of Date header formats to display.
Valid formats are `ut' (universal time), `local' (local time
zone), `english' (readable English), `lapsed' (elapsed time),
`combined-lapsed' (both the original date and the elapsed time),
`original' (the original date header), `iso8601' (ISO8601
format), and `user-defined' (a user-defined format defined by the
`gnus-article-time-format' variable).

You have as many date headers as you want in the article buffer.
Some of these headers are updated automatically. See
`gnus-article-update-date-headers' for details.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.1 of Emacs.