AttributeError 'NoneType' object has no attribute 'strftime'

[Almad]

https://almad.sentry.io/share/issue/b2d4e56e79ff485d9971409f42459763/

User without a creation time: https://nove.dracidoupe.cz/uzivatel/6577-t/

  File "django/template/base.py", line 703, in resolve
    new_obj = func(obj, *arg_vals)
  File "ddcz/templatetags/creations.py", line 68, in articleTime
    return datetime.strftime("%-d. %-m. %Y v %-H:%M")

[Saro259]

Is datetime passed as an argument? or as a module?... If passed as an argument an object creation might resolve the problem.