Hello, This issue was discovered on Kolla train-centos8 images, but I assume it applies to both Train and Ussuri for CentOS 8 in general, not just to Kolla. CloudKitty became timezone-aware in Train: https://review.opendev.org/#/c/669192/ This code references tz.UTC from the dateutil library. However, this was added only in dateutil 2.7.0, while train-centos8 Kolla images use package python3-dateutil-2.6.1-6.el8.noarch.rpm, causing the error captured at the end of this message [2]. I submitted a patch to raise the minimum requirement for dateutil in cloudkitty: https://review.opendev.org/#/c/742477/ However, how are those requirements taken into consideration when packaging OpenStack in RDO? RDO packages for CentOS7 provide python2-dateutil-2.8.0-1.el7.noarch.rpm, but there is no such package in the CentOS8 repository. Would it be better to just remove the use of tz.UTC? I believe we could use dateutil.tz.tzutc() instead. Thanks, Pierre Riteau (priteau) [1] http://mirror.centos.org/centos/8/cloud/x86_64/openstack-train/Packages/p/ [2] Error trace below: 2020-07-22 16:33:11.207 26 ERROR wsme.api [req-3c49884a-1412-42bb-a57e-e7c731360148 ef450a969a2945928d3ade785eaae860 19df0f36ede14c29be9ca476222f8ba9 default - -] Server-side error: "module 'dateutil.tz' has no attribute 'UTC'". Detail: Traceback (most recent call last): File "/usr/lib/python3.6/site-packages/wsmeext/pecan.py", line 85, in callfunction result = f(self, *args, **kwargs) File "/usr/lib/python3.6/site-packages/cloudkitty/api/v1/controllers/storage.py", line 71, in get_all paginate=False) File "/usr/lib/python3.6/site-packages/cloudkitty/storage/v2/influx.py", line 311, in retrieve begin, end = self._check_begin_end(begin, end) File "/usr/lib/python3.6/site-packages/cloudkitty/storage/v2/influx.py", line 271, in _check_begin_end end = tzutils.get_next_month() File "/usr/lib/python3.6/site-packages/cloudkitty/tzutils.py", line 150, in get_next_month return add_delta(start, datetime.timedelta(days=month_days)) File "/usr/lib/python3.6/site-packages/cloudkitty/tzutils.py", line 104, in add_delta return utc_to_local(local_to_utc(dt, naive=True) + delta) File "/usr/lib/python3.6/site-packages/cloudkitty/tzutils.py", line 52, in local_to_utc output = dt.astimezone(tz.UTC) AttributeError: module 'dateutil.tz' has no attribute 'UTC'