Since I fixed the timezone on the DokuWiki server, its no longer possible to use OpenLDAP to login.
I tried the fixes from the following page, but no changes:
https://www.dokuwiki.org/tips:timezone
# php --version
PHP 7.0.30-0+deb9u1 (cli) (built: Jun 14 2018 13:50:25) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2017 Zend Technologies
with Zend OPcache v7.0.30-0+deb9u1, Copyright (c) 1999-2017, by Zend Technologies
# nginx -v
nginx version: nginx/1.10.3
# apt show slapd
Package: slapd
Version: 2.4.44+dfsg-5+deb9u2
Priority: optional
Section: net
Source: openldap
Maintainer: Debian OpenLDAP Maintainers <pkg-openldap-devel@lists.alioth.debian.org>
Installed-Size: 11.5 MB
Provides: ldap-server, libslapi-2.4-2
Pre-Depends: debconf (>= 0.5) | debconf-2.0
Depends: libc6 (>= 2.12), libdb5.3, libgnutls30 (>= 3.5.0), libldap-2.4-2 (= 2.4.44+dfsg-5+deb9u2), libltdl7 (>= 2.4.6), libodbc1 (>= 2.3.1), libperl5.24 (>= 5.24.0), libsasl2-2, libwrap0 (>= 7.6-4~), coreutils (>= 4.5.1-1), psmisc, perl (>> 5.8.0) | libmime-base64-perl, adduser, lsb-base (>= 3.2-13)