>>> "EB" == Emanuel Berg <incal@dataswamp.org> writes:

> Uwe Brauer wrote:
>> a simple describe-variable suggests to use 
>> 
>> (defun my-changelog-date-format (&optional time zone)
>> (format-time-string "%Y-%m-%d %H:%M"))
>> 
>> Which indeed worked

> What time zone is that?

None, 

The code in add-log reads

(defun add-log-iso8601-time-zone (&optional time zone)
  (declare (obsolete nil "26.1"))
  (format-time-string "%:::z" time zone))

(defvar add-log-iso8601-with-time-zone nil)

(defun add-log-iso8601-time-string (&optional time zone)
  (format-time-string
   (if add-log-iso8601-with-time-zone "%Y-%m-%d %:::z" "%Y-%m-%d") time zone))

Since I don't think I will ever use time zones, I did not bother to set
this right up.

-- 
I strongly condemn Putin's war of aggression against the Ukraine.
I support to deliver weapons to Ukraine's military. 
I support the ban of Russia from SWIFT.
I support the EU membership of the Ukraine.