Here is a workaround:
As I understand it the /etc/timezone contains a timezone name, which should be the path to a file relative to /usr/share/zoneinfo. /etc/localtime is a symbolic link that is pointing to same file under /usr/share/zoneinfo/.
With the Unraid 7.0.0 update, Unraid has removed that particular legacy path (/etc/timezone).
Glance and the clock widget work fine for me and the error in appdata backup has been solved with this workaround.
@ZappyZap It would be cool if you could look into if the Docker Path Timezone is still required.
Cheers